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Sample records for proximal cortical thickness

  1. Increased cortical porosity and reduced cortical thickness of the proximal femur are associated with nonvertebral fracture independent of Fracture Risk Assessment Tool and Garvan estimates in postmenopausal women.

    Science.gov (United States)

    Kral, Rita; Osima, Marit; Borgen, Tove T; Vestgaard, Roald; Richardsen, Elin; Bjørnerem, Åshild

    2017-01-01

    The Fracture Risk Assessment Tool (FRAX) and Garvan Calculator have improved the individual prediction of fracture risk. However, additional bone measurements that might enhance the predictive ability of these tools are the subject of research. There is increasing interest in cortical parameters, especially cortical porosity. Neither FRAX nor Garvan include measurements of cortical architecture, important for bone strength, and providing independent information beyond the conventional approaches. We tested the hypothesis that cortical parameters are associated with fracture risk, independent of FRAX and Garvan estimates. This nested case-control study included 211 postmenopausal women aged 54-94 years with nonvertebral fractures, and 232 controls from the Tromsø Study in Norway. We assessed FRAX and Garvan 10-year risk estimates for fragility fracture, and quantified femoral subtrochanteric cortical porosity, thickness, and area from computed tomography images using StrAx1.0 software. Per standard deviation higher cortical porosity, thinner cortices, and smaller cortical area, the odds ratio (95% confidence interval) for fracture was 1.71 (1.38-2.11), 1.79 (1.44-2.23), and 1.52 (1.19-1.95), respectively. Cortical porosity and thickness, but not area, remained associated with fracture when adjusted for FRAX and Garvan estimates. Adding cortical porosity and thickness to FRAX or Garvan resulted in greater area under the receiver operating characteristic curves. When using cortical porosity (>80th percentile) or cortical thickness (20%), 45.5% and 42.7% of fracture cases were identified, respectively. Using the same cutoffs for cortical porosity or thickness combined with Garvan (threshold >25%), 51.2% and 48.3% were identified, respectively. Specificity for all combinations ranged from 81.0-83.6%. Measurement of cortical porosity or thickness identified 20.4% and 17.5% additional fracture cases that, were unidentified using FRAX alone, and 16.6% and 13.7% fracture

  2. Increased cortical porosity and reduced cortical thickness of the proximal femur are associated with nonvertebral fracture independent of Fracture Risk Assessment Tool and Garvan estimates in postmenopausal women.

    Directory of Open Access Journals (Sweden)

    Rita Kral

    Full Text Available The Fracture Risk Assessment Tool (FRAX and Garvan Calculator have improved the individual prediction of fracture risk. However, additional bone measurements that might enhance the predictive ability of these tools are the subject of research. There is increasing interest in cortical parameters, especially cortical porosity. Neither FRAX nor Garvan include measurements of cortical architecture, important for bone strength, and providing independent information beyond the conventional approaches. We tested the hypothesis that cortical parameters are associated with fracture risk, independent of FRAX and Garvan estimates. This nested case-control study included 211 postmenopausal women aged 54-94 years with nonvertebral fractures, and 232 controls from the Tromsø Study in Norway. We assessed FRAX and Garvan 10-year risk estimates for fragility fracture, and quantified femoral subtrochanteric cortical porosity, thickness, and area from computed tomography images using StrAx1.0 software. Per standard deviation higher cortical porosity, thinner cortices, and smaller cortical area, the odds ratio (95% confidence interval for fracture was 1.71 (1.38-2.11, 1.79 (1.44-2.23, and 1.52 (1.19-1.95, respectively. Cortical porosity and thickness, but not area, remained associated with fracture when adjusted for FRAX and Garvan estimates. Adding cortical porosity and thickness to FRAX or Garvan resulted in greater area under the receiver operating characteristic curves. When using cortical porosity (>80th percentile or cortical thickness (20%, 45.5% and 42.7% of fracture cases were identified, respectively. Using the same cutoffs for cortical porosity or thickness combined with Garvan (threshold >25%, 51.2% and 48.3% were identified, respectively. Specificity for all combinations ranged from 81.0-83.6%. Measurement of cortical porosity or thickness identified 20.4% and 17.5% additional fracture cases that, were unidentified using FRAX alone, and 16.6% and 13

  3. Distribution of bone density and cortical thickness in the proximal femur and their association with hip fracture in postmenopausal women: a quantitative computed tomography study.

    Science.gov (United States)

    Yang, L; Udall, W J M; McCloskey, E V; Eastell, R

    2014-01-01

    The quantitative computed tomography (QCT) scans in an individually matched case-control study of women with hip fracture were analysed. There were widespread deficits in the femoral volumetric bone mineral density (vBMD) and cortical thickness of cases, and cortical vBMD and thickness discriminated hip fracture independently of BMD by dual-energy X-ray absorptiometry (DXA). Acknowledging the limitations of QCT associated with partial volume effects, we used QCT in an individually matched case-control study of women with hip fracture to better understand its structural basis. Fifty postmenopausal women (55-89 years) who had sustained hip fractures due to low-energy trauma underwent QCT scans of the contralateral hip within 3 months of the fracture. For each case, postmenopausal women, matched by age (±5 years), weight (±5 kg) and height (±5 cm), were recruited as controls. We quantified cortical, trabecular and integral vBMD and apparent cortical thickness (AppCtTh) in four quadrants of cross-sections along the length of the femoral head (FH), femoral neck (FN), intertrochanter and trochanter and examined their association with hip fracture. Women with hip or intracapsular (IC) fracture had significantly (p fractures independent of hip areal BMD (aBMD). The combination of AppCtTh and trabecular or integral vBMD discriminated hip fracture, whereas the combination of FH and FN AppCtTh discriminated IC fracture significantly (p fracture independently of aBMD by DXA.

  4. Cortical thickness abnormalities in late adolescence with online gaming addiction

    National Research Council Canada - National Science Library

    Yuan, Kai; Cheng, Ping; Dong, Tao; Bi, Yanzhi; Xing, Lihong; Yu, Dahua; Zhao, Limei; Dong, Minghao; von Deneen, Karen M; Liu, Yijun; Qin, Wei; Tian, Jie

    2013-01-01

    ...) and age-, education- and gender-matched controls (n = 18) were acquired. The cortical thickness measurement method was employed to investigate alterations of cortical thickness in individuals with online gaming addiction...

  5. Reduced cortical thickness in gambling disorder

    DEFF Research Database (Denmark)

    Grant, Jon E; Odlaug, Brian Lawrence; Chamberlain, Samuel R

    2015-01-01

    Gambling disorder has recently been recognized as a prototype 'behavioral addiction' by virtue of its inclusion in the DSM-5 category of 'Substance-Related and Addictive Disorders.' Despite its newly acquired status and prevalence rate of 1-3 % globally, relatively little is known regarding...... the neurobiology of this disorder. The aim of this study was to explore cortical morphometry in untreated gambling disorder, for the first time. Subjects with gambling disorder (N = 16) free from current psychotropic medication or psychiatric comorbidities, and healthy controls (N = 17), were entered...... into the study and undertook magnetic resonance imaging (3T MRI). Cortical thickness was quantified using automated segmentation techniques (FreeSurfer), and group differences were identified using permutation cluster analysis, with stringent correction for multiple comparisons. Gambling disorder was associated...

  6. The Hounsfield value for cortical bone geometry in the proximal humerus - an in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Lim Fat, Daren; Kennedy, Jim; Galvin, Rose; O' Brien, Fergal; Mc Grath, Frank; Mullett, Hannan [Royal College of Surgeons in Ireland, Investigations Carried Out at Anatomy Lab, Dublin (Ireland)

    2012-05-15

    Fractures of the proximal humerus represent a major osteoporotic burden. Recent developments in CT imaging have emphasized the importance of cortical bone thickness distribution in the prevention and management of fragility fractures. We aimed to experimentally define the CT density of cortical bone in the proximal humerus for building cortical geometry maps. With ethical approval, we used ten fresh-frozen human proximal humeri. These were stripped of all soft tissue and high-resolution CT images were then taken. The humeral heads were then subsequently resected to allow access to the metaphyseal area. Using curettes, cancellous bone was removed down to hard cortical bone. Another set of CT images of the reamed specimen was then taken. Using CT imaging software and a CAD interface, we then compared cortical contours at different CT density thresholds to the reference inner cortical contour of our reamed specimens. Working with 3D model representations of these cortical maps, we were able to accurately make distance comparison analyses based on different CT thresholds. We could compute a single closest value at 700 HU. No difference was found in the HU-based contours generated along the 500-900 HU pixels (p = 1.000). The contours were significantly different from those generated at 300, 400, 1,000, and 1,100 HU. A Hounsfield range of 500-900 HU can accurately depict cortical bone geometry in the proximal humerus. Thresholding outside this range leads to statistically significant inaccuracies. Our results concur with a similar range reported in the literature for the proximal femur. Knowledge of regional variations in cortical bone thickness has direct implications for basic science studies on osteoporosis and its treatment, but is also important for the orthopedic surgeon since our decision for treatment options is often guided by local bone quality. (orig.)

  7. Cortical Thickness Abnormalities in Late Adolescence with Online Gaming Addiction

    Science.gov (United States)

    Yuan, Kai; Cheng, Ping; Dong, Tao; Bi, Yanzhi; Xing, Lihong; Yu, Dahua; Zhao, Limei; Dong, Minghao; von Deneen, Karen M.; Liu, Yijun; Qin, Wei; Tian, Jie

    2013-01-01

    Online gaming addiction, as the most popular subtype of Internet addiction, had gained more and more attention from the whole world. However, the structural differences in cortical thickness of the brain between adolescents with online gaming addiction and healthy controls are not well unknown; neither was its association with the impaired cognitive control ability. High-resolution magnetic resonance imaging scans from late adolescence with online gaming addiction (n = 18) and age-, education- and gender-matched controls (n = 18) were acquired. The cortical thickness measurement method was employed to investigate alterations of cortical thickness in individuals with online gaming addiction. The color-word Stroop task was employed to investigate the functional implications of the cortical thickness abnormalities. Imaging data revealed increased cortical thickness in the left precentral cortex, precuneus, middle frontal cortex, inferior temporal and middle temporal cortices in late adolescence with online gaming addiction; meanwhile, the cortical thicknesses of the left lateral orbitofrontal cortex (OFC), insula, lingual gyrus, the right postcentral gyrus, entorhinal cortex and inferior parietal cortex were decreased. Correlation analysis demonstrated that the cortical thicknesses of the left precentral cortex, precuneus and lingual gyrus correlated with duration of online gaming addiction and the cortical thickness of the OFC correlated with the impaired task performance during the color-word Stroop task in adolescents with online gaming addiction. The findings in the current study suggested that the cortical thickness abnormalities of these regions may be implicated in the underlying pathophysiology of online gaming addiction. PMID:23326379

  8. Cortical thickness abnormalities in late adolescence with online gaming addiction.

    Science.gov (United States)

    Yuan, Kai; Cheng, Ping; Dong, Tao; Bi, Yanzhi; Xing, Lihong; Yu, Dahua; Zhao, Limei; Dong, Minghao; von Deneen, Karen M; Liu, Yijun; Qin, Wei; Tian, Jie

    2013-01-01

    Online gaming addiction, as the most popular subtype of Internet addiction, had gained more and more attention from the whole world. However, the structural differences in cortical thickness of the brain between adolescents with online gaming addiction and healthy controls are not well unknown; neither was its association with the impaired cognitive control ability. High-resolution magnetic resonance imaging scans from late adolescence with online gaming addiction (n = 18) and age-, education- and gender-matched controls (n = 18) were acquired. The cortical thickness measurement method was employed to investigate alterations of cortical thickness in individuals with online gaming addiction. The color-word Stroop task was employed to investigate the functional implications of the cortical thickness abnormalities. Imaging data revealed increased cortical thickness in the left precentral cortex, precuneus, middle frontal cortex, inferior temporal and middle temporal cortices in late adolescence with online gaming addiction; meanwhile, the cortical thicknesses of the left lateral orbitofrontal cortex (OFC), insula, lingual gyrus, the right postcentral gyrus, entorhinal cortex and inferior parietal cortex were decreased. Correlation analysis demonstrated that the cortical thicknesses of the left precentral cortex, precuneus and lingual gyrus correlated with duration of online gaming addiction and the cortical thickness of the OFC correlated with the impaired task performance during the color-word Stroop task in adolescents with online gaming addiction. The findings in the current study suggested that the cortical thickness abnormalities of these regions may be implicated in the underlying pathophysiology of online gaming addiction.

  9. Cortical thickness abnormalities in late adolescence with online gaming addiction.

    Directory of Open Access Journals (Sweden)

    Kai Yuan

    Full Text Available Online gaming addiction, as the most popular subtype of Internet addiction, had gained more and more attention from the whole world. However, the structural differences in cortical thickness of the brain between adolescents with online gaming addiction and healthy controls are not well unknown; neither was its association with the impaired cognitive control ability. High-resolution magnetic resonance imaging scans from late adolescence with online gaming addiction (n = 18 and age-, education- and gender-matched controls (n = 18 were acquired. The cortical thickness measurement method was employed to investigate alterations of cortical thickness in individuals with online gaming addiction. The color-word Stroop task was employed to investigate the functional implications of the cortical thickness abnormalities. Imaging data revealed increased cortical thickness in the left precentral cortex, precuneus, middle frontal cortex, inferior temporal and middle temporal cortices in late adolescence with online gaming addiction; meanwhile, the cortical thicknesses of the left lateral orbitofrontal cortex (OFC, insula, lingual gyrus, the right postcentral gyrus, entorhinal cortex and inferior parietal cortex were decreased. Correlation analysis demonstrated that the cortical thicknesses of the left precentral cortex, precuneus and lingual gyrus correlated with duration of online gaming addiction and the cortical thickness of the OFC correlated with the impaired task performance during the color-word Stroop task in adolescents with online gaming addiction. The findings in the current study suggested that the cortical thickness abnormalities of these regions may be implicated in the underlying pathophysiology of online gaming addiction.

  10. Reduced orbitofrontal cortical thickness in male adolescents with internet addiction

    National Research Council Canada - National Science Library

    Hong, Soon-Beom; Kim, Jae-Won; Choi, Eun-Jung; Kim, Ho-Hyun; Suh, Jeong-Eun; Kim, Chang-Dai; Klauser, Paul; Whittle, Sarah; Yűcel, Murat; Pantelis, Christos; Yi, Soon-Hyung

    2013-01-01

    .... However, no study to date has examined OFC thickness in internet addiction. In the current study, we investigated the existence of differences in cortical thickness of the OFC in adolescents with internet addiction...

  11. Technical Note: Cortical thickness and density estimation from clinical CT using a prior thickness-density relationship

    Energy Technology Data Exchange (ETDEWEB)

    Humbert, Ludovic, E-mail: ludohumberto@gmail.com [Galgo Medical, Barcelona 08036 (Spain); Hazrati Marangalou, Javad; Rietbergen, Bert van [Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands); Río Barquero, Luis Miguel del [CETIR Centre Medic, Barcelona 08029 (Spain); Lenthe, G. Harry van [Biomechanics Section, KU Leuven–University of Leuven, Leuven 3001 (Belgium)

    2016-04-15

    Purpose: Cortical thickness and density are critical components in determining the strength of bony structures. Computed tomography (CT) is one possible modality for analyzing the cortex in 3D. In this paper, a model-based approach for measuring the cortical bone thickness and density from clinical CT images is proposed. Methods: Density variations across the cortex were modeled as a function of the cortical thickness and density, location of the cortex, density of surrounding tissues, and imaging blur. High resolution micro-CT data of cadaver proximal femurs were analyzed to determine a relationship between cortical thickness and density. This thickness-density relationship was used as prior information to be incorporated in the model to obtain accurate measurements of cortical thickness and density from clinical CT volumes. The method was validated using micro-CT scans of 23 cadaver proximal femurs. Simulated clinical CT images with different voxel sizes were generated from the micro-CT data. Cortical thickness and density were estimated from the simulated images using the proposed method and compared with measurements obtained using the micro-CT images to evaluate the effect of voxel size on the accuracy of the method. Then, 19 of the 23 specimens were imaged using a clinical CT scanner. Cortical thickness and density were estimated from the clinical CT images using the proposed method and compared with the micro-CT measurements. Finally, a case-control study including 20 patients with osteoporosis and 20 age-matched controls with normal bone density was performed to evaluate the proposed method in a clinical context. Results: Cortical thickness (density) estimation errors were 0.07 ± 0.19 mm (−18 ± 92 mg/cm{sup 3}) using the simulated clinical CT volumes with the smallest voxel size (0.33 × 0.33 × 0.5 mm{sup 3}), and 0.10 ± 0.24 mm (−10 ± 115 mg/cm{sup 3}) using the volumes with the largest voxel size (1.0 × 1.0 × 3.0 mm{sup 3}). A trend for the

  12. Allostatic load and reduced cortical thickness in schizophrenia.

    Science.gov (United States)

    Chiappelli, Joshua; Kochunov, Peter; Savransky, Anya; Fisseha, Feven; Wisner, Krista; Du, Xiaoming; Rowland, Laura M; Hong, L Elliot

    2017-03-01

    Structural imaging studies have consistently found reduced gray matter thickness of the cerebral cortex in schizophrenia, a finding that is evident in first episode psychosis and may be progressive in some cases. Although genetic predisposition and medication effects may contribute to cortical thinning, we hypothesize that the cumulative effects of stress may represent an environmental factor impacting brain morphology in schizophrenia. We examined the relationship between allostatic load, an index of peripheral biomarkers representing the cumulative effects of stress, and cortical thickness. Allostatic load was calculated for 44 patients with schizophrenia spectrum disorders (SSD) and 33 normal controls (NC) based on 13 cardiovascular, neuroendocrine, immune, and metabolic measurements. Controlling for age, SSD had significantly elevated allostatic load as compared with NC (p=0.008). Controlling for age, whole brain average cortical thickness was lower in SSD patients compared to NC (p=0.008). However, once allostatic load was accounted for, the group difference in cortical thickness became marginal (p=0.058). Exploratory analyses on subcomponents of allostatic load suggested that elevated immune marker C-reactive protein, stress hormones, and cardiovascular indices within allostatic load were more strongly associated with reduced cortical thickness in SSD. In NC, only the association between immune marker C-reactive protein and cortical thickness was replicated. These results support the hypothesis that allostatic load may account for some of the gray matter deficits observed in schizophrenia. Among the allostatic indices, the inflammatory mechanism appears particularly relevant to cortical thickness in both schizophrenia patients and normal controls. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Longitudinal changes in cortical thickness in autism and typical development

    Science.gov (United States)

    Prigge, Molly B. D.; Nielsen, Jared A.; Froehlich, Alyson L.; Abildskov, Tracy J.; Anderson, Jeffrey S.; Fletcher, P. Thomas; Zygmunt, Kristen M.; Travers, Brittany G.; Lange, Nicholas; Alexander, Andrew L.; Bigler, Erin D.; Lainhart, Janet E.

    2014-01-01

    The natural history of brain growth in autism spectrum disorders remains unclear. Cross-sectional studies have identified regional abnormalities in brain volume and cortical thickness in autism, although substantial discrepancies have been reported. Preliminary longitudinal studies using two time points and small samples have identified specific regional differences in cortical thickness in the disorder. To clarify age-related trajectories of cortical development, we examined longitudinal changes in cortical thickness within a large mixed cross-sectional and longitudinal sample of autistic subjects and age- and gender-matched typically developing controls. Three hundred and forty-five magnetic resonance imaging scans were examined from 97 males with autism (mean age = 16.8 years; range 3–36 years) and 60 males with typical development (mean age = 18 years; range 4–39 years), with an average interscan interval of 2.6 years. FreeSurfer image analysis software was used to parcellate the cortex into 34 regions of interest per hemisphere and to calculate mean cortical thickness for each region. Longitudinal linear mixed effects models were used to further characterize these findings and identify regions with between-group differences in longitudinal age-related trajectories. Using mean age at time of first scan as a reference (15 years), differences were observed in bilateral inferior frontal gyrus, pars opercularis and pars triangularis, right caudal middle frontal and left rostral middle frontal regions, and left frontal pole. However, group differences in cortical thickness varied by developmental stage, and were influenced by IQ. Differences in age-related trajectories emerged in bilateral parietal and occipital regions (postcentral gyrus, cuneus, lingual gyrus, pericalcarine cortex), left frontal regions (pars opercularis, rostral middle frontal and frontal pole), left supramarginal gyrus, and right transverse temporal gyrus, superior parietal lobule, and

  14. On the homogeneity and heterogeneity of cortical thickness profiles in Homo sapiens sapiens.

    Science.gov (United States)

    Koten, Jan Willem; Schüppen, André; Morozova, Maria; Lehofer, Agnes; Koschutnig, Karl; Wood, Guilherme

    2017-12-20

    Cortical thickness has been investigated since the beginning of the 20th century, but we do not know how similar the cortical thickness profiles among humans are. In this study, the local similarity of cortical thickness profiles was investigated using sliding window methods. Here, we show that approximately 5% of the cortical thickness profiles are similarly expressed among humans while 45% of the cortical thickness profiles show a high level of heterogeneity. Therefore, heterogeneity is the rule, not the exception. Cortical thickness profiles of somatosensory homunculi and the anterior insula are consistent among humans, while the cortical thickness profiles of the motor homunculus are more variable. Cortical thickness profiles of homunculi that code for muscle position and skin stimulation are highly similar among humans despite large differences in sex, education, and age. This finding suggests that the structure of these cortices remains well preserved over a lifetime. Our observations possibly relativize opinions on cortical plasticity.

  15. Influence of trabecular microstructure and cortical index on the complexity of proximal humeral fractures.

    Science.gov (United States)

    Osterhoff, Georg; Diederichs, Gerd; Tami, Andrea; Theopold, Jan; Josten, Christoph; Hepp, Pierre

    2012-04-01

    Poor bone quality increases the susceptibility to fractures of the proximal humerus. It is unclear whether local trabecular and cortical measures influence the severity of fracture patterns. The goal of this study was to assess parameters of trabecular and cortical bone properties and to compare these parameters with the severity of fractures and biomechanical testing. Twenty patients with displaced proximal humeral fractures planned for osteosynthesis were included. Fractures were classified as either 2-part fractures or complex fractures. Bone after core drilling was harvested during surgery from the humeral head in each patient. Twenty bone cores obtained from nonpaired cadaver humeral heads served as nonfractured controls. Micro-CT (μCT) was performed and bone volume/total volume (BV/TV), connectivity density (CD), trabecular number (Tb.N), trabecular thickness (Tb.Th), trabecular spacing (Tb.Sp), and bone mineral density (BMD) were assessed. The cortical index (CI) was determined from AP plain films. Biomechanical testing was done after μCT scanning by axially loading until failure, and ultimate strength and E modulus were recorded. BV/TV, BMD and CD showed moderate to strong correlations with biomechanical testing (r = 0.45-0.76, all p fracture groups and controls regarding μCT and biomechanical parameters. CI was not significantly different between the 2-part and complex fracture groups. In our study population local trabecular bone structure and cortical index could not predict the severity of proximal humeral fractures in the elderly. Complex fractures do not necessarily imply lower bone quality compared to simple fractures.

  16. Cortical thickness and brain volumetric analysis in body dysmorphic disorder.

    Science.gov (United States)

    Madsen, Sarah K; Zai, Alex; Pirnia, Tara; Arienzo, Donatello; Zhan, Liang; Moody, Teena D; Thompson, Paul M; Feusner, Jamie D

    2015-04-30

    Individuals with body dysmorphic disorder (BDD) suffer from preoccupations with perceived defects in physical appearance, causing severe distress and disability. Although BDD affects 1-2% of the population, the neurobiology is not understood. Discrepant results in previous volumetric studies may be due to small sample sizes, and no study has investigated cortical thickness in BDD. The current study is the largest neuroimaging analysis of BDD. Participants included 49 medication-free, right-handed individuals with DSM-IV BDD and 44 healthy controls matched by age, sex, and education. Using high-resolution T1-weighted magnetic resonance imaging, we computed vertex-wise gray matter (GM) thickness on the cortical surface and GM volume using voxel-based morphometry. We also computed volumes in cortical and subcortical regions of interest. In addition to group comparisons, we investigated associations with symptom severity, insight, and anxiety within the BDD group. In BDD, greater anxiety was significantly associated with thinner GM in the left superior temporal cortex and greater GM volume in the right caudate nucleus. There were no significant differences in cortical thickness, GM volume, or volumes in regions of interest between BDD and control subjects. Subtle associations with clinical symptoms may characterize brain morphometric patterns in BDD, rather than large group differences in brain structure. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Reduced cortical thickness associated with visceral fat and BMI.

    Science.gov (United States)

    Veit, Ralf; Kullmann, Stephanie; Heni, Martin; Machann, Jürgen; Häring, Hans-Ulrich; Fritsche, Andreas; Preissl, Hubert

    2014-01-01

    Structural brain imaging studies have shown that obesity is associated with widespread reductions in gray matter (GM) volume. Although the body mass index (BMI) is an easily accessible anthropometric measure, substantial health problems are more related to specific body fat compartments, like visceral adipose tissue (VAT). We investigated cortical thickness measures in a group of 72 healthy subjects (BMI range 20-35 kg/m(2), age range 19-50 years). Multiple regression analyses were performed using VAT and BMI as predictors and age, gender, total surface area and education as confounds. BMI and VAT were independently associated with reductions in cortical thickness in clusters comprising the left lateral occipital area, the left inferior temporal cortex, and the left precentral and inferior parietal area, while the right insula, the left fusiform gyrus and the right inferior temporal area showed a negative correlation with VAT only. In addition, we could show significant reductions in cortical thickness with increasing VAT adjusted for BMI in the left temporal cortex. We were able to detect widespread cortical thinning in a young to middle-aged population related to BMI and VAT; these findings show close resemblance to studies focusing on GM volume differences in diabetic patients. This may point to the influence of VAT related adverse effects, like low-grade inflammation, as a potentially harmful factor on brain integrity already in individuals at risk of developing diabetes, metabolic syndromes and arteriosclerosis.

  18. Reduced cortical thickness associated with visceral fat and BMI

    Directory of Open Access Journals (Sweden)

    Ralf Veit

    2014-01-01

    Full Text Available Structural brain imaging studies have shown that obesity is associated with widespread reductions in gray matter (GM volume. Although the body mass index (BMI is an easily accessible anthropometric measure, substantial health problems are more related to specific body fat compartments, like visceral adipose tissue (VAT. We investigated cortical thickness measures in a group of 72 healthy subjects (BMI range 20–35 kg/m2, age range 19–50 years. Multiple regression analyses were performed using VAT and BMI as predictors and age, gender, total surface area and education as confounds. BMI and VAT were independently associated with reductions in cortical thickness in clusters comprising the left lateral occipital area, the left inferior temporal cortex, and the left precentral and inferior parietal area, while the right insula, the left fusiform gyrus and the right inferior temporal area showed a negative correlation with VAT only. In addition, we could show significant reductions in cortical thickness with increasing VAT adjusted for BMI in the left temporal cortex. We were able to detect widespread cortical thinning in a young to middle-aged population related to BMI and VAT; these findings show close resemblance to studies focusing on GM volume differences in diabetic patients. This may point to the influence of VAT related adverse effects, like low-grade inflammation, as a potentially harmful factor on brain integrity already in individuals at risk of developing diabetes, metabolic syndromes and arteriosclerosis.

  19. Effect of age at onset on cortical thickness and cognition in posterior cortical atrophy.

    Science.gov (United States)

    Suárez-González, Aida; Lehmann, Manja; Shakespeare, Timothy J; Yong, Keir X X; Paterson, Ross W; Slattery, Catherine F; Foulkes, Alexander J M; Rabinovici, Gil D; Gil-Néciga, Eulogio; Roldán-Lora, Florinda; Schott, Jonathan M; Fox, Nick C; Crutch, Sebastian J

    2016-08-01

    Age at onset (AAO) has been shown to influence the phenotype of Alzheimer's disease (AD), but how it affects atypical presentations of AD remains unknown. Posterior cortical atrophy (PCA) is the most common form of atypical AD. In this study, we aimed to investigate the effect of AAO on cortical thickness and cognitive function in 98 PCA patients. We used Freesurfer (v5.3.0) to compare cortical thickness with AAO both as a continuous variable, and by dichotomizing the groups based on median age (58 years). In both the continuous and dichotomized analyses, we found a pattern suggestive of thinner cortex in precuneus and parietal areas in earlier-onset PCA, and lower cortical thickness in anterior cingulate and prefrontal cortex in later-onset PCA. These cortical thickness differences between PCA subgroups were consistent with earlier-onset PCA patients performing worse on cognitive tests involving parietal functions. Our results provide a suggestion that AAO may not only affect the clinico-anatomical characteristics in AD but may also affect atrophy patterns and cognition within atypical AD phenotypes. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Early detection of AD using cortical thickness measurements

    Science.gov (United States)

    Spjuth, M.; Gravesen, F.; Eskildsen, S. F.; Østergaard, L. R.

    2007-03-01

    Alzheimer's disease (AD) is a neurodegenerative disorder that causes cortical atrophy and impaired cognitive functions. The diagnosis is difficult to make and is often made over a longer period of time using a combination of neuropsychological tests, and structural and functional imaging. Due to the impact of early intervention the challenge of distinguishing early AD from normal ageing has received increasing attention. This study uses cortical thickness measurements to characterize the atrophy in nine mild AD patients (mean MMSE-score 23.3 (std: 2.6)) compared to five healthy middle-aged subjects. A fully automated method based on deformable models is used for delineation of the inner and outer boundaries of the cerebral cortex from Magnetic Resonance Images. This allows observer independent high-resolution quantification of the cortical thickness. The cortex analysis facilitates detection of alterations throughout the entire cortical mantle. To perform inter-subject thickness comparison in which the spatial information is retained, a feature-based registration algorithm is developed which uses local cortical curvature, normal vector, and a distance measure. A comparison of the two study groups reveals that the lateral side of the hemispheres shows diffuse thinner areas in the mild AD group but especially the medial side shows a pronounced thinner area which can be explained by early limbic changes in AD. For classification principal component analysis is applied to reduce the high number of thickness measurements (>200,000) into fewer features. All mild AD and healthy middle-aged subjects are classified correctly (sensitivity and specificity 100%).

  1. Reduced cortical thickness associated with visceral fat and BMI

    OpenAIRE

    Veit, Ralf; Kullmann, Stephanie; Heni, Martin; Machann, Jürgen; Häring, Hans-Ulrich; Fritsche, Andreas; Preissl, Hubert

    2014-01-01

    Structural brain imaging studies have shown that obesity is associated with widespread reductions in gray matter (GM) volume. Although the body mass index (BMI) is an easily accessible anthropometric measure, substantial health problems are more related to specific body fat compartments, like visceral adipose tissue (VAT). We investigated cortical thickness measures in a group of 72 healthy subjects (BMI range 20–35 kg/m2, age range 19–50 years). Multiple regression analyses were performed us...

  2. Crown dimensions and proximal enamel thickness of mandibular second bicuspids

    Directory of Open Access Journals (Sweden)

    Sérgio Augusto Fernandes

    2011-08-01

    Full Text Available To achieve proper recontouring of anterior and posterior teeth, to obtain optimal morphology during enamel stripping, it is important to be aware of dental anatomy. This study aimed at evaluating crown dimensions and proximal enamel thickness in a sample of 40 extracted sound, human, mandibular, second bicuspids (20 right and 20 left. Mesiodistal, cervico-occlusal and buccolingual crown dimensions were measured using a digital caliper, accurate to 0.01 mm. Teeth were embedded in acrylic resin and cut along their long axes through the proximal surfaces to obtain 0.7 mm-thick central sections. Enamel thickness on the cut sections was measured using a perfilometer. Comparative analyses were carried out using the Student's-t test (α= 5%. The mean mesiodistal crown widths for right and left teeth were 7.79 mm (± 0.47 and 7.70 mm (± 0.51, respectively. Mean cervico-occlusal heights ranged from 8.31 mm (± 0.75 on the right to 8.38 mm (± 0.85 on the left teeth. The mean values for the buccolingual dimension were 8.67 mm (± 0.70 on the right and 8.65 mm (± 0.54 on the left teeth. The mean enamel thickness on the mesial surfaces ranged from 1.35 mm (± 0.22 to 1.40 mm (± 0.17, on the left and right sides, respectively. On the distal surfaces, the corresponding values were 1.44 mm (± 0.21 and 1.46 mm (± 0.12. No significant differences were found between measurements for right and left teeth. However, enamel thickness was significantly greater on the distal surfaces, compared with the mesial surfaces.

  3. Cortical thickness abnormalities associated with dyslexia, independent of remediation status

    Science.gov (United States)

    Ma, Yizhou; Koyama, Maki S.; Milham, Michael P.; Castellanos, F. Xavier; Quinn, Brian T.; Pardoe, Heath; Wang, Xiuyuan; Kuzniecky, Ruben; Devinsky, Orrin; Thesen, Thomas; Blackmon, Karen

    2014-01-01

    Abnormalities in cortical structure are commonly observed in children with dyslexia in key regions of the “reading network.” Whether alteration in cortical features reflects pathology inherent to dyslexia or environmental influence (e.g., impoverished reading experience) remains unclear. To address this question, we compared MRI-derived metrics of cortical thickness (CT), surface area (SA), gray matter volume (GMV), and their lateralization across three different groups of children with a historical diagnosis of dyslexia, who varied in current reading level. We compared three dyslexia subgroups with: (1) persistent reading and spelling impairment; (2) remediated reading impairment (normal reading scores), and (3) remediated reading and spelling impairments (normal reading and spelling scores); and a control group of (4) typically developing children. All groups were matched for age, gender, handedness, and IQ. We hypothesized that the dyslexia group would show cortical abnormalities in regions of the reading network relative to controls, irrespective of remediation status. Such a finding would support that cortical abnormalities are inherent to dyslexia and are not a consequence of abnormal reading experience. Results revealed increased CT of the left fusiform gyrus in the dyslexia group relative to controls. Similarly, the dyslexia group showed CT increase of the right superior temporal gyrus, extending into the planum temporale, which resulted in a rightward CT asymmetry on lateralization indices. There were no group differences in SA, GMV, or their lateralization. These findings held true regardless of remediation status. Each reading level group showed the same “double hit” of atypically increased left fusiform CT and rightward superior temporal CT asymmetry. Thus, findings provide evidence that a developmental history of dyslexia is associated with CT abnormalities, independent of remediation status. PMID:25610779

  4. Effect of intrinsic and extrinsic factors on global and regional cortical thickness.

    Directory of Open Access Journals (Sweden)

    Koushik A Govindarajan

    Full Text Available Global and regional cortical thicknesses based on T1-weighted magnetic resonance images acquired at 1.5 T and 3 T were measured on a relatively large cohort of 295 subjects using FreeSurfer software. Multivariate regression analysis was performed using Pillai's trace test to determine significant differences in cortical thicknesses measured at these two field strengths. Our results indicate that global cortical thickness is not affected by the field strength or gender. In contrast, the regional cortical thickness was observed to be field dependent. Specifically, the cortical thickness in regions such as parahippocampal, superior temporal, precentral and posterior cingulate is thicker at 3 T than at 1.5 T. In contrast regions such as cuneus and pericalcarine showed higher cortical thickness at 1.5 T than at 3 T. These differences appear to be age-dependent. The differences in regional cortical thickness between field strengths were similar in both genders. Further, male vs. female differences in regional cortical thickness were observed only at 1.5 T and not at 3 T. Our results indicate that magnetic field strength has a significant effect on the estimation of regional, but not global, cortical thickness. In addition, the pulse sequence, scanner type, and spatial resolution do not appear to have significant effect on the measured cortical thickness.

  5. Effect of intrinsic and extrinsic factors on global and regional cortical thickness.

    Science.gov (United States)

    Govindarajan, Koushik A; Freeman, Leorah; Cai, Chunyan; Rahbar, Mohammad H; Narayana, Ponnada A

    2014-01-01

    Global and regional cortical thicknesses based on T1-weighted magnetic resonance images acquired at 1.5 T and 3 T were measured on a relatively large cohort of 295 subjects using FreeSurfer software. Multivariate regression analysis was performed using Pillai's trace test to determine significant differences in cortical thicknesses measured at these two field strengths. Our results indicate that global cortical thickness is not affected by the field strength or gender. In contrast, the regional cortical thickness was observed to be field dependent. Specifically, the cortical thickness in regions such as parahippocampal, superior temporal, precentral and posterior cingulate is thicker at 3 T than at 1.5 T. In contrast regions such as cuneus and pericalcarine showed higher cortical thickness at 1.5 T than at 3 T. These differences appear to be age-dependent. The differences in regional cortical thickness between field strengths were similar in both genders. Further, male vs. female differences in regional cortical thickness were observed only at 1.5 T and not at 3 T. Our results indicate that magnetic field strength has a significant effect on the estimation of regional, but not global, cortical thickness. In addition, the pulse sequence, scanner type, and spatial resolution do not appear to have significant effect on the measured cortical thickness.

  6. Cortical thickness and surface area relate to specific symptoms in early relapsing-remitting multiple sclerosis.

    Science.gov (United States)

    Nygaard, Gro O; Walhovd, Kristine B; Sowa, Piotr; Chepkoech, Joy-Loi; Bjørnerud, Atle; Due-Tønnessen, Paulina; Landrø, Nils I; Damangir, Soheil; Spulber, Gabriela; Storsve, Andreas B; Beyer, Mona K; Fjell, Anders M; Celius, Elisabeth G; Harbo, Hanne F

    2015-04-01

    Cortical atrophy is common in early relapsing-remitting multiple sclerosis (RRMS). Whether this atrophy is caused by changes in cortical thickness or cortical surface area is not known, nor is their separate contributions to clinical symptoms. To investigate the difference in cortical surface area, thickness and volume between early RRMS patients and healthy controls; and the relationship between these measures and neurological disability, cognitive decline, fatigue and depression. RRMS patients (n = 61) underwent magnetic resonance imaging (MRI), neurological and neuropsychological examinations. We estimated cortical surface area, thickness and volume and compared them with matched healthy controls (n = 61). We estimated the correlations between clinical symptoms and cortical measures within the patient group. We found no differences in cortical surface area, but widespread differences in cortical thickness and volume between the groups. Neurological disability was related to regionally smaller cortical thickness and volume. Better verbal memory was related to regionally larger surface area; and better visuo-spatial memory, to regionally larger cortical volume. Higher depression scores and fatigue were associated with regionally smaller cortical surface area and volume. We found that cortical thickness, but not cortical surface area, is affected in early RRMS. We identified specific structural correlates to the main clinical symptoms in early RRMS. © The Author(s), 2014.

  7. Sexual orientation related differences in cortical thickness in male individuals.

    Science.gov (United States)

    Abé, Christoph; Johansson, Emilia; Allzén, Elin; Savic, Ivanka

    2014-01-01

    Previous neuroimaging studies demonstrated sex and also sexual orientation related structural and functional differences in the human brain. Genetic information and effects of sex hormones are assumed to contribute to the male/female differentiation of the brain, and similar effects could play a role in processes influencing human's sexual orientation. However, questions about the origin and development of a person's sexual orientation remain unanswered, and research on sexual orientation related neurobiological characteristics is still very limited. To contribute to a better understanding of the neurobiology of sexual orientation, we used magnetic resonance imaging (MRI) in order to compare regional cortical thickness (Cth) and subcortical volumes of homosexual men (hoM), heterosexual men (heM) and heterosexual women (heW). hoM (and heW) had thinner cortices primarily in visual areas and smaller thalamus volumes than heM, in which hoM and heW did not differ. Our results support previous studies, which suggest cerebral differences between hoM and heM in regions, where sex differences have been reported, which are frequently proposed to underlie biological mechanisms. Thus, our results contribute to a better understanding of the neurobiology of sexual orientation.

  8. Sexual orientation related differences in cortical thickness in male individuals.

    Directory of Open Access Journals (Sweden)

    Christoph Abé

    Full Text Available Previous neuroimaging studies demonstrated sex and also sexual orientation related structural and functional differences in the human brain. Genetic information and effects of sex hormones are assumed to contribute to the male/female differentiation of the brain, and similar effects could play a role in processes influencing human's sexual orientation. However, questions about the origin and development of a person's sexual orientation remain unanswered, and research on sexual orientation related neurobiological characteristics is still very limited. To contribute to a better understanding of the neurobiology of sexual orientation, we used magnetic resonance imaging (MRI in order to compare regional cortical thickness (Cth and subcortical volumes of homosexual men (hoM, heterosexual men (heM and heterosexual women (heW. hoM (and heW had thinner cortices primarily in visual areas and smaller thalamus volumes than heM, in which hoM and heW did not differ. Our results support previous studies, which suggest cerebral differences between hoM and heM in regions, where sex differences have been reported, which are frequently proposed to underlie biological mechanisms. Thus, our results contribute to a better understanding of the neurobiology of sexual orientation.

  9. Left Renal Cortical Thickness Measured by Ultrasound Can Predict Early Progression of Chronic Kidney Disease.

    Science.gov (United States)

    Takata, Tomoaki; Koda, Masahiko; Sugihara, Takaaki; Sugihara, Shinobu; Okamoto, Toshiaki; Miyoshi, Kenichi; Hodotsuka, Masanori; Fujise, Yuki; Matono, Tomomitsu; Okano, Junichi; Hosho, Keiko; Iyama, Takuji; Fukui, Takeaki; Fukuda, Satoko; Munemura, Chishio; Isomoto, Hajime

    2016-01-01

    The kidney becomes atrophic in advanced chronic kidney disease, and renal size and parenchymal volume correlate with renal function. However, alterations in renal parenchymal volume have not been adequately studied in terms of the renal cortex and medulla. We investigated the relationship between the changes in the renal cortex and medulla and renal function. Renal ultrasound (US) parameters including renal length, parenchymal thickness, cortical thickness and medullary thickness were assessed in 176 subjects, who were categorized into 4 groups based on the estimated glomerular filtration rate (ml/min/1.73 m2): group 1, ≥ 90; group 2, ≥ 60 but < 90; group 3, ≥ 30 but < 60; and group 4, < 30. Renal US parameters in both kidneys were compared among the 4 groups. We found stepwise associations in renal length, cortical thickness and parenchymal thickness with decreased renal function. Medullary thickness showed no changes among groups 1-3. Multiple linear regression analysis including sex, age and renal US parameters showed that only renal length was an independent predictor of renal function. When analyzed in groups 1-3, cortical thickness was the strongest associated parameter. Lower cortical left/right ratio (left cortical thickness/right cortical thickness) showed a stepwise association with a decrease in renal function. Renal length and cortical thickness measured by US were correlated with renal function. In particular, left cortical thickness could help to detect early changes in renal function. © 2015 S. Karger AG, Basel.

  10. Changes in cortical volumetric bone mineral density and thickness, and trabecular thickness in lactating women postpartum.

    Science.gov (United States)

    Brembeck, P; Lorentzon, M; Ohlsson, C; Winkvist, A; Augustin, H

    2015-02-01

    Lactation is associated with decreased areal bone mineral density (aBMD). Replenishment occurs especially after ceased lactation. Changes in volumetric bone mineral density (vBMD), microstructure, and dimensional parameters are unknown and may clarify the role of lactation for skeletal health. OBJECTIVE AND MAIN OUTCOMES: The objective of the study was to test the hypothesis that lactation is associated with changes in aBMD, vBMD, microstructure, and dimensional parameters. At baseline (0.5 mo after delivery) and 4, 12, and 18 months thereafter, bone was assessed using dual-energy x-ray absorptiometry and high-resolution peripheral quantitative computed tomography. Eighty-one fair-skinned postpartum women and 21 controls aged 25-40 years were recruited. The completion ratio was 73%. Postpartum women were categorized depending on duration of lactation: 0-3.9, 4-8.9, and 9 months or longer. During the first 4 months, aBMD decreased at several sites (geometric mean ± SE; -0.73% ± 0.21% to -3.98% ± 0.76%) in women lactating at least 4 months. During the same time, cortical vBMD at the ultradistal tibia decreased in women lactating 4-8.9 months (-0.26% ± 0.08%) and 9 months or longer (-0.49% ± 0.10%). At 12 months postpartum, cortical thickness (≥ 9 mo, -2.48% ± 0.41%) and trabecular thickness (4-8.9 mo, -2.14% ± 0.92%; ≥ 9 mo, -2.56% ± 1.21%) also were lower than baseline. No decreases were found in women lactating less than 4 months or in controls in these parameters. At 18 months postpartum, both cortical vBMD (≥ 9 mo, -0.77% ± 0.17%) and trabecular thickness (4-8.9 mo, -2.25% ± 1.25%; ≥ 9 mo, -3.21% ± 1.41%) were lower in women with long lactation. Decreases in cortical vBMD, thickness, and trabecular thickness at the ultradistal tibia were found in women lactating 4 months or longer. Longer follow-up is needed to confirm whether women with extended lactation recover fully or whether the changes could potentially lead to an increased risk of

  11. Bone Density and Cortical Thickness in Normal, Osteopenic, and Osteoporotic Sacra

    Directory of Open Access Journals (Sweden)

    Andrew M. Richards

    2010-01-01

    Full Text Available It is unclear if a decrease in cancellous bone density or cortical bone thickness is related to sacral insufficiency fractures. We hypothesized that reduction in overall bone density leads to local reductions in bone density and cortical thickness in cadaveric sacra that match clinically observed fracture patterns in patients with sacral insufficiency fractures. We used quantitative computed tomography to measure cancellous density and cortical thickness in multiple areas of normal, osteopenic, and osteoporotic sacra. Cancellous bone density was significantly lower in osteoporotic specimens in the central and anterior regions of the sacral ala compared with other regions of these specimens. Cortical thickness decreased uniformly in all regions of osteopenic and osteoporotic specimens. These results support our hypothesis that areas of the sacrum where sacral insufficiency fractures often occur have significantly larger decreases in cancellous bone density; however, they do not support the hypothesis that these areas have local reduction of cortical bone thickness.

  12. Development and aging of cortical thickness correspond to genetic organization patterns.

    Science.gov (United States)

    Fjell, Anders M; Grydeland, Håkon; Krogsrud, Stine K; Amlien, Inge; Rohani, Darius A; Ferschmann, Lia; Storsve, Andreas B; Tamnes, Christian K; Sala-Llonch, Roser; Due-Tønnessen, Paulina; Bjørnerud, Atle; Sølsnes, Anne Elisabeth; Håberg, Asta K; Skranes, Jon; Bartsch, Hauke; Chen, Chi-Hua; Thompson, Wesley K; Panizzon, Matthew S; Kremen, William S; Dale, Anders M; Walhovd, Kristine B

    2015-12-15

    There is a growing realization that early life influences have lasting impact on brain function and structure. Recent research has demonstrated that genetic relationships in adults can be used to parcellate the cortex into regions of maximal shared genetic influence, and a major hypothesis is that genetically programmed neurodevelopmental events cause a lasting impact on the organization of the cerebral cortex observable decades later. Here we tested how developmental and lifespan changes in cortical thickness fit the underlying genetic organizational principles of cortical thickness in a longitudinal sample of 974 participants between 4.1 and 88.5 y of age with a total of 1,633 scans, including 773 scans from children below 12 y. Genetic clustering of cortical thickness was based on an independent dataset of 406 adult twins. Developmental and adult age-related changes in cortical thickness followed closely the genetic organization of the cerebral cortex, with change rates varying as a function of genetic similarity between regions. Cortical regions with overlapping genetic architecture showed correlated developmental and adult age change trajectories and vice versa for regions with low genetic overlap. Thus, effects of genes on regional variations in cortical thickness in middle age can be traced to regional differences in neurodevelopmental change rates and extrapolated to further adult aging-related cortical thinning. This finding suggests that genetic factors contribute to cortical changes through life and calls for a lifespan perspective in research aimed at identifying the genetic and environmental determinants of cortical development and aging.

  13. Associations between cortical thickness and general intelligence in children, adolescents and young adults

    Science.gov (United States)

    Menary, Kyle; Collins, Paul F.; Porter, James N.; Muetzel, Ryan; Olson, Elizabeth A.; Kumar, Vipin; Steinbach, Michael; Lim, Kelvin O.; Luciana, Monica

    2013-01-01

    Neuroimaging research indicates that human intellectual ability is related to brain structure including the thickness of the cerebral cortex. Most studies indicate that general intelligence is positively associated with cortical thickness in areas of association cortex distributed throughout both brain hemispheres. In this study, we performed a cortical thickness mapping analysis on data from 182 healthy typically developing males and females ages 9 to 24 years to identify correlates of general intelligence (g) scores. To determine if these correlates also mediate associations of specific cognitive abilities with cortical thickness, we regressed specific cognitive test scores on g scores and analyzed the residuals with respect to cortical thickness. The effect of age on the association between cortical thickness and intelligence was examined. We found a widely distributed pattern of positive associations between cortical thickness and g scores, as derived from the first unrotated principal factor of a factor analysis of Wechsler Abbreviated Scale of Intelligence (WASI) subtest scores. After WASI specific cognitive subtest scores were regressed on g factor scores, the residual score variances did not correlate significantly with cortical thickness in the full sample with age covaried. When participants were grouped at the age median, significant positive associations of cortical thickness were obtained in the older group for g-residualized scores on Block Design (a measure of visual-motor integrative processing) while significant negative associations of cortical thickness were observed in the younger group for g-residualized Vocabulary scores. These results regarding correlates of general intelligence are concordant with the existing literature, while the findings from younger versus older subgroups have implications for future research on brain structural correlates of specific cognitive abilities, as well as the cognitive domain specificity of behavioral

  14. Associations between cortical thickness and general intelligence in children, adolescents and young adults.

    Science.gov (United States)

    Menary, Kyle; Collins, Paul F; Porter, James N; Muetzel, Ryan; Olson, Elizabeth A; Kumar, Vipin; Steinbach, Michael; Lim, Kelvin O; Luciana, Monica

    2013-09-01

    Neuroimaging research indicates that human intellectual ability is related to brain structure including the thickness of the cerebral cortex. Most studies indicate that general intelligence is positively associated with cortical thickness in areas of association cortex distributed throughout both brain hemispheres. In this study, we performed a cortical thickness mapping analysis on data from 182 healthy typically developing males and females ages 9 to 24 years to identify correlates of general intelligence (g) scores. To determine if these correlates also mediate associations of specific cognitive abilities with cortical thickness, we regressed specific cognitive test scores on g scores and analyzed the residuals with respect to cortical thickness. The effect of age on the association between cortical thickness and intelligence was examined. We found a widely distributed pattern of positive associations between cortical thickness and g scores, as derived from the first unrotated principal factor of a factor analysis of Wechsler Abbreviated Scale of Intelligence (WASI) subtest scores. After WASI specific cognitive subtest scores were regressed on g factor scores, the residual score variances did not correlate significantly with cortical thickness in the full sample with age covaried. When participants were grouped at the age median, significant positive associations of cortical thickness were obtained in the older group for g-residualized scores on Block Design (a measure of visual-motor integrative processing) while significant negative associations of cortical thickness were observed in the younger group for g-residualized Vocabulary scores. These results regarding correlates of general intelligence are concordant with the existing literature, while the findings from younger versus older subgroups have implications for future research on brain structural correlates of specific cognitive abilities, as well as the cognitive domain specificity of behavioral

  15. Macrostructural brain changes in patients with longstanding type 1 diabetes mellitus - a cortical thickness analysis study

    DEFF Research Database (Denmark)

    Frøkjær, J B; Brock, C; Søfteland, E

    2013-01-01

    Longstanding diabetes mellitus (DM) is associated with the risk of complications affecting the central nervous system. The aims were to study brain volume and cortical thickness in regional brain areas in DM patients and to correlate the findings with relevant clinical data.15 patients...... with longstanding (average 24.6 years) type 1 DM and 20 healthy controls were studied in a 3T magnetic resonance scanner. Using an automated surface based cortical segmentation method, cortical thickness was assessed in anatomical regions including total and lobe-wise grey and white matter volumes. Also...... morphological changes were evaluated.No differences between patients and controls were found in regard to number of white matter lesions (P=0.50), grey and white matter volumes (P=0.25) and overall cortical thickness (P=0.64). Subanalysis revealed exclusively reduced cortical thickness of the postcentral (P=0...

  16. Age-Related Differences in Cortical Thickness Vary by Socioeconomic Status.

    Directory of Open Access Journals (Sweden)

    Luciane R Piccolo

    Full Text Available Recent findings indicate robust associations between socioeconomic status (SES and brain structure in children, raising questions about the ways in which SES may modify structural brain development. In general, cortical thickness and surface area develop in nonlinear patterns across childhood and adolescence, with developmental patterns varying to some degree by cortical region. Here, we examined whether age-related nonlinear changes in cortical thickness and surface area varied by SES, as indexed by family income and parental education. We hypothesized that SES disparities in age-related change may be particularly evident for language- and literacy-supporting cortical regions. Participants were 1148 typically-developing individuals between 3 and 20 years of age. Results indicated that SES factors moderate patterns of age-associated change in cortical thickness but not surface area. Specifically, at lower levels of SES, associations between age and cortical thickness were curvilinear, with relatively steep age-related decreases in cortical thickness earlier in childhood, and subsequent leveling off during adolescence. In contrast, at high levels of SES, associations between age and cortical thickness were linear, with consistent reductions across the age range studied. Notably, this interaction was prominent in the left fusiform gyrus, a region that is critical for reading development. In a similar pattern, SES factors significantly moderated linear age-related change in left superior temporal gyrus, such that higher SES was linked with steeper age-related decreases in cortical thickness in this region. These findings suggest that SES may moderate patterns of age-related cortical thinning, especially in language- and literacy-supporting cortical regions.

  17. Age-Related Differences in Cortical Thickness Vary by Socioeconomic Status.

    Science.gov (United States)

    Piccolo, Luciane R; Merz, Emily C; He, Xiaofu; Sowell, Elizabeth R; Noble, Kimberly G

    2016-01-01

    Recent findings indicate robust associations between socioeconomic status (SES) and brain structure in children, raising questions about the ways in which SES may modify structural brain development. In general, cortical thickness and surface area develop in nonlinear patterns across childhood and adolescence, with developmental patterns varying to some degree by cortical region. Here, we examined whether age-related nonlinear changes in cortical thickness and surface area varied by SES, as indexed by family income and parental education. We hypothesized that SES disparities in age-related change may be particularly evident for language- and literacy-supporting cortical regions. Participants were 1148 typically-developing individuals between 3 and 20 years of age. Results indicated that SES factors moderate patterns of age-associated change in cortical thickness but not surface area. Specifically, at lower levels of SES, associations between age and cortical thickness were curvilinear, with relatively steep age-related decreases in cortical thickness earlier in childhood, and subsequent leveling off during adolescence. In contrast, at high levels of SES, associations between age and cortical thickness were linear, with consistent reductions across the age range studied. Notably, this interaction was prominent in the left fusiform gyrus, a region that is critical for reading development. In a similar pattern, SES factors significantly moderated linear age-related change in left superior temporal gyrus, such that higher SES was linked with steeper age-related decreases in cortical thickness in this region. These findings suggest that SES may moderate patterns of age-related cortical thinning, especially in language- and literacy-supporting cortical regions.

  18. Association between age of disease-onset, cognitive performance and cortical thickness in bipolar disorders.

    Science.gov (United States)

    Oertel-Knöchel, Viola; Reuter, Johanna; Reinke, Britta; Marbach, Katharina; Feddern, Richard; Alves, Gilberto; Prvulovic, David; Linden, David E J; Knöchel, Christian

    2015-03-15

    Neuroimaging studies in patients with bipolar disorder (BD) have indicated a number of structural brain changes, including reduced cortical thickness. However, the effects of the course of illness, clinical and cognitive variables on cortical thickness in BD patients have not yet been evaluated. A total of 67 individuals (32 patients with euthymic BD and 35 healthy and age-matched controls) underwent 3D-anatomical magnetic resonance imaging (MRI). Whole-brain cortical thickness and group differences were assessed using the Freesurfer software. Course of disease variables, clinical and cognitive parameters were correlated with cortical thickness measures. We found reduced cortical thickness in BD patients compared with controls in the frontal and temporal lobes and in several limbic areas. We also report significant associations between cortical thickness and age of disease-onset, speed of cognitive processing, executive function and depression severity in BD patients. Cortical thickness reduction across frontal and limbic areas is a structural correlate of affective symptom severity and cognitive impairments in BD as well of age of disease-onset. We may assume that frontal lobe structural abnormalities are present in bipolar disorder, and might lead to dysfunctional cognitive functioning. The causality and functional relevance beyond mere correlation, however, is yet to be established. Our findings encourage further longitudinal studies in BD patients and in healthy at-risk subjects in order to discern the temporal order and development of morphological changes and clinical symptoms. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Cortical thickness of the femur and long-term bisphosphonate use.

    Science.gov (United States)

    Niimi, Rui; Kono, Toshibumi; Nishihara, Atsushi; Hasegawa, Masahiro; Matsumine, Akihiko; Kono, Toshihiko; Sudo, Akihiro

    2015-02-01

    Femoral cortical thickening has been mentioned in reports of atypical subtrochanteric/femoral shaft (ST/FS) fractures, which are associated with long-term bisphosphonate (BP) use. However, whether thickening precedes BP use or results from BP use, as well as the role BPs may play in cortical thickening remain unclear. The purpose of this study was to investigate the relationship between cortical thickness and BP use. We enrolled 142 patients (mean age 79 years) who had taken BPs for more than 5 years, and enrolled 426 osteoporosis patients who had not used BPs as controls. We performed a case-control study of patients with long-term BP use and controls matched for age, sex, and levels of activities of daily living (ADLs) (1:3 ratio). On femoral radiographs, we measured femoral cortical thickness in three regions: 5 cm and 12.5 cm below the lesser trochanter and in the region of maximal cortical thickness. We compared cortical thicknesses between patients taking BP and controls and evaluated longitudinal changes in cortical thickness. There were no significant differences in cortical thickness between long-term BP users and controls. In addition, after further use of BP for a minimum of 1 year, we observed no significant differences in the changes in cortical thickness at any level of the femur. In conclusion, our study did not find evidence of cortical thickening at the ST/FS area of the femur with long-term BP use. © 2014 American Society for Bone and Mineral Research.

  20. Cognitive function, P3a/P3b brain potentials, and cortical thickness in aging.

    Science.gov (United States)

    Fjell, Anders M; Walhovd, Kristine B; Fischl, Bruce; Reinvang, Ivar

    2007-11-01

    The purpose of the study was to assess the relationship between the P3a/P3b brain potentials, cortical thickness, and cognitive function in aging. Thirty-five younger and 37 older healthy participants completed a visual three-stimuli oddball ERP (event-related potential)-paradigm, a battery of neuropsychological tests, and MRI scans. Groups with short vs. long latency, and low vs. high amplitude, were compared on a point by point basis across the entire cortical mantle. In the young, thickness was only weakly related to P3. In the elderly, P3a amplitude effects were found in parietal areas, the temporoparietal junction, and parts of the posterior cingulate cortex. P3b latency was especially related to cortical thickness in large frontal regions. Path models with the whole sample pooled together were constructed, demonstrating that cortical thickness in the temporoparietal cortex predicted P3a amplitude, which in turn predicted executive function, and that thickness in orbitofrontal cortex predicted P3b latency, which in turn predicted fluid function. When age was included in the model, the relationship between P3 and cognitive function vanished, while the relationship between regional cortical thickness and P3 remained. It is concluded that thickness in specific cortical areas correlates with scalp recorded P3a/P3b in elderly, and that these relationships differentially mediate higher cognitive function. Copyright 2007 Wiley-Liss, Inc.

  1. Heritability analysis of surface-based cortical thickness estimation on a large twin cohort

    Science.gov (United States)

    Shen, Kaikai; Doré, Vincent; Rose, Stephen; Fripp, Jurgen; McMahon, Katie L.; de Zubicaray, Greig I.; Martin, Nicholas G.; Thompson, Paul M.; Wright, Margaret J.; Salvado, Olivier

    2015-03-01

    The aim of this paper is to assess the heritability of cerebral cortex, based on measurements of grey matter (GM) thickness derived from structural MR images (sMRI). With data acquired from a large twin cohort (328 subjects), an automated method was used to estimate the cortical thickness, and EM-ICP surface registration algorithm was used to establish the correspondence of cortex across the population. An ACE model was then employed to compute the heritability of cortical thickness. Heritable cortical thickness measures various cortical regions, especially in frontal and parietal lobes, such as bilateral postcentral gyri, superior occipital gyri, superior parietal gyri, precuneus, the orbital part of the right frontal gyrus, right medial superior frontal gyrus, right middle occipital gyrus, right paracentral lobule, left precentral gyrus, and left dorsolateral superior frontal gyrus.

  2. Brain volumes and regional cortical thickness in young females with anorexia nervosa

    OpenAIRE

    Fuglset, Tone S; Endestad, Tor; Hilland, Eva; Bang, Lasse; Tamnes, Christian K.; Nils I Landrø; Rø, Øyvind

    2016-01-01

    Background Anorexia nervosa (AN) is a severe mental illness, with an unknown etiology. Magnetic resonance imaging studies show reduced brain volumes and cortical thickness in patients compared to healthy controls. However, findings are inconsistent, especially concerning the anatomical location and extent of the differences. The purpose of this study was to estimate and compare brain volumes and regional cortical thickness in young females with AN and healthy controls. ...

  3. Altered brain structural networks in attention deficit/hyperactivity disorder children revealed by cortical thickness.

    Science.gov (United States)

    Liu, Tian; Chen, Yanni; Li, Chenxi; Li, Youjun; Wang, Jue

    2017-07-04

    This study investigated the cortical thickness and topological features of human brain anatomical networks related to attention deficit/hyperactivity disorder. Data were collected from 40 attention deficit/hyperactivity disorder children and 40 normal control children. Interregional correlation matrices were established by calculating the correlations of cortical thickness between all pairs of cortical regions (68 regions) of the whole brain. Further thresholds were applied to create binary matrices to construct a series of undirected and unweighted graphs, and global, local, and nodal efficiencies were computed as a function of the network cost. These experimental results revealed abnormal cortical thickness and correlations in attention deficit/hyperactivity disorder, and showed that the brain structural networks of attention deficit/hyperactivity disorder subjects had inefficient small-world topological features. Furthermore, their topological properties were altered abnormally. In particular, decreased global efficiency combined with increased local efficiency in attention deficit/hyperactivity disorder children led to a disorder-related shift of the network topological structure toward regular networks. In addition, nodal efficiency, cortical thickness, and correlation analyses revealed that several brain regions were altered in attention deficit/hyperactivity disorder patients. These findings are in accordance with a hypothesis of dysfunctional integration and segregation of the brain in patients with attention deficit/hyperactivity disorder and provide further evidence of brain dysfunction in attention deficit/hyperactivity disorder patients by observing cortical thickness on magnetic resonance imaging.

  4. Reduced Cortical Thickness in the Temporal Pole, Insula, and Pars Triangularis in Patients with Panic Disorder.

    Science.gov (United States)

    Kang, Eun Kyoung; Lee, Kang Soo; Lee, Sang Hyuk

    2017-09-01

    Recent neuroimaging findings have revealed that paralimbic and prefrontal regions are involved in panic disorder (PD). However, no imaging studies have compared differences in cortical thickness between patients with PD and healthy control (HC) subjects. Forty-seven right-handed patients with PD who met the diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders-4th edition-text revision, and 30 HC subjects were enrolled. We used the FreeSurfer software package for estimating the cortical thickness of regions of interest, including the temporal pole, insula, and pars triangularis (mid-ventrolateral prefrontal cortex). Cortical thickness of the temporal pole (p=0.033, right), insula (p=0.017, left), and pars triangularis (p=0.008, left; p=0.025, right) in patients with PD was significantly lower, compared with HC subjects (Benjamini-Hochberg false discovery rate correction). Exploratory analysis revealed a significant negative correlation between the cortical thickness of the right temporal pole and Beck Depression Inventory scores (r=-0.333, p=0.027) in patients with PD and positive correlations between the cortical thickness of the left pars triangularis and Panic Disorder Severity Scale (r=0.429, p=0.004), Anxiety Sensitivity Index-Revised (r=0.380, p=0.011), and Beck Anxiety Inventory (r=0.421, p=0.004) scores using Pearson's correlation. Ours study is the first to demonstrate cortical thickness reduction in the temporal pole, insula, and pars triangularis in patients with PD, compared with the HC subjects. These findings suggest that reduced cortical thickness could play an important role in the pathophysiology of PD.

  5. 4D segmentation of brain MR images with constrained cortical thickness variation.

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    Li Wang

    Full Text Available Segmentation of brain MR images plays an important role in longitudinal investigation of developmental, aging, disease progression changes in the cerebral cortex. However, most existing brain segmentation methods consider multiple time-point images individually and thus cannot achieve longitudinal consistency. For example, cortical thickness measured from the segmented image will contain unnecessary temporal variations, which will affect the time related change pattern and eventually reduce the statistical power of analysis. In this paper, we propose a 4D segmentation framework for the adult brain MR images with the constraint of cortical thickness variations. Specifically, we utilize local intensity information to address the intensity inhomogeneity, spatial cortical thickness constraint to maintain the cortical thickness being within a reasonable range, and temporal cortical thickness variation constraint in neighboring time-points to suppress the artificial variations. The proposed method has been tested on BLSA dataset and ADNI dataset with promising results. Both qualitative and quantitative experimental results demonstrate the advantage of the proposed method, in comparison to other state-of-the-art 4D segmentation methods.

  6. Effect of in-painting on cortical thickness measurements in multiple sclerosis: A large cohort study.

    Science.gov (United States)

    Govindarajan, Koushik A; Datta, Sushmita; Hasan, Khader M; Choi, Sangbum; Rahbar, Mohammad H; Cofield, Stacey S; Cutter, Gary R; Lublin, Fred D; Wolinsky, Jerry S; Narayana, Ponnada A

    2015-10-01

    A comprehensive analysis of the effect of lesion in-painting on the estimation of cortical thickness using magnetic resonance imaging was performed on a large cohort of 918 relapsing-remitting multiple sclerosis patients who participated in a phase III multicenter clinical trial. An automatic lesion in-painting algorithm was developed and implemented. Cortical thickness was measured using the FreeSurfer pipeline with and without in-painting. The effect of in-painting was evaluated using FreeSurfer's paired analysis pipeline. Multivariate regression analysis was also performed with field strength and lesion load as additional factors. Overall, the estimated cortical thickness was different with in-painting than without. The effect of in-painting was observed to be region dependent, more significant in the left hemisphere compared to the right, was more prominent at 1.5 T relative to 3 T, and was greater at higher lesion volumes. Our results show that even for data acquired at 1.5 T in patients with high lesion load, the mean cortical thickness difference with and without in-painting is ∼2%. Based on these results, it appears that in-painting has only a small effect on the estimated regional and global cortical thickness. Hum Brain Mapp 36:3749-3760, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  7. Childhood cognitive ability accounts for associations between cognitive ability and brain cortical thickness in old age.

    Science.gov (United States)

    Karama, S; Bastin, M E; Murray, C; Royle, N A; Penke, L; Muñoz Maniega, S; Gow, A J; Corley, J; Valdés Hernández, M del C; Lewis, J D; Rousseau, M-É; Lepage, C; Fonov, V; Collins, D L; Booth, T; Rioux, P; Sherif, T; Adalat, R; Starr, J M; Evans, A C; Wardlaw, J M; Deary, I J

    2014-05-01

    Associations between brain cortical tissue volume and cognitive function in old age are frequently interpreted as suggesting that preservation of cortical tissue is the foundation of successful cognitive aging. However, this association could also, in part, reflect a lifelong association between cognitive ability and cortical tissue. We analyzed data on 588 subjects from the Lothian Birth Cohort 1936 who had intelligence quotient (IQ) scores from the same cognitive test available at both 11 and 70 years of age as well as high-resolution brain magnetic resonance imaging data obtained at approximately 73 years of age. Cortical thickness was estimated at 81 924 sampling points across the cortex for each subject using an automated pipeline. Multiple regression was used to assess associations between cortical thickness and the IQ measures at 11 and 70 years. Childhood IQ accounted for more than two-third of the association between IQ at 70 years and cortical thickness measured at age 73 years. This warns against ascribing a causal interpretation to the association between cognitive ability and cortical tissue in old age based on assumptions about, and exclusive reference to, the aging process and any associated disease. Without early-life measures of cognitive ability, it would have been tempting to conclude that preservation of cortical thickness in old age is a foundation for successful cognitive aging when, instead, it is a lifelong association. This being said, results should not be construed as meaning that all studies on aging require direct measures of childhood IQ, but as suggesting that proxy measures of prior cognitive function can be useful to take into consideration.

  8. Brain-derived neurotrophic factor promoter methylation and cortical thickness in recurrent major depressive disorder.

    Science.gov (United States)

    Na, Kyoung-Sae; Won, Eunsoo; Kang, June; Chang, Hun Soo; Yoon, Ho-Kyoung; Tae, Woo Suk; Kim, Yong-Ku; Lee, Min-Soo; Joe, Sook-Haeng; Kim, Hyun; Ham, Byung-Joo

    2016-02-15

    Recent studies have reported that methylation of the brain-derived neurotrophic factor (BDNF) gene promoter is associated with major depressive disorder (MDD). This study aimed to investigate the association between cortical thickness and methylation of BDNF promoters as well as serum BDNF levels in MDD. The participants consisted of 65 patients with recurrent MDD and 65 age- and gender-matched healthy controls. Methylation of BDNF promoters and cortical thickness were compared between the groups. The right medial orbitofrontal, right lingual, right lateral occipital, left lateral orbitofrontal, left pars triangularis, and left lingual cortices were thinner in patients with MDD than in healthy controls. Among the MDD group, right pericalcarine, right medical orbitofrontal, right rostral middle frontal, right postcentral, right inferior temporal, right cuneus, right precuneus, left frontal pole, left superior frontal, left superior temporal, left rostral middle frontal and left lingual cortices had inverse correlations with methylation of BDNF promoters. Higher levels of BDNF promoter methylation may be closely associated with the reduced cortical thickness among patients with MDD. Serum BDNF levels were significantly lower in MDD, and showed an inverse relationship with BDNF methylation only in healthy controls. Particularly the prefrontal and occipital cortices seem to indicate key regions in which BDNF methylation has a significant effect on structure.

  9. An Experimental Study of Radiographic Density of Alveolar Bone and Cortical Thickness of Mandible by Osteoporosis

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    Lee, Byeong Do [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Wonkwang University, Iksan (Korea, Republic of)

    2000-12-15

    To evaluate the effect of the systemic osteoporosis on radiographic density of alveolar bone and cortical thickness of mandible. The bone mineral density values of lumbar and femur were measured by dual-energy X-ray absorptiometry and T scores of lumbar, femur were obtained respectively. Radiographic densities of alveolar bones and panorama mandibular index (PMI, represents as cortical thickness) were analysed statistically according to age and T score variavles. The radiographic density of alveolar bone of maxillary molar showed significant difference by age and femur T group. That of mandibular molar showed significant difference between femur T group. Panorama mandibular index showed significant difference between age groups. The radiographic density of alvealar bones was more dependent on age femur T than lumbar T. Cortical thickness of mandible was correlated with increasing age.

  10. The Comparison of Dentine Thickness Under Proximal Caries Between Bitewing Radiographs and Tooth Structure

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    Khosravi K

    2001-05-01

    Full Text Available Carious lesions are usually found by dentists, using bitewing radiographs, and according to the depth of the lesions, the treatment plan is designed. At the present, this technique is the most accepted one and is used generally. But it is not a perfect technique and there are some errors in determining of depth of proximal carious lesions. These errors are mainly related to the use of new high-speed films with broad density and lower voltages. In this study, dentin thickness under proximal caries in bitewing radiography was compared with its real thickness, in tooth structure. Twenty-four teeth samples with proximal caries were used. Before and after removal of carious lesions bitewing radiographs were taken and then each tooth was sectioned occlusogingivally and the thickness of dentine under proximal caries and on bitewing radiographs were measured under microscope with 0.01 mm accuracy. Mean value of dentine thickness in tooth structure was 41% of its mean thickness in bitewing radiographs, showing 59% difference (reduction. Therefore, more care should be taken in using standard technique and interpreting of bitewing radiographs by clinicians. Clinical examinations also should be performed in ideal conditions, and patients should be clinically and radiographically examined every six months.

  11. Genetic and environmental influences on cortical surface area and cortical thickness in bipolar disorder

    NARCIS (Netherlands)

    Bootsman, F.; Brouwer, R. M.; Schnack, H. G.; van Baal, G. C. M.; van der Schot, A. C.; Vonk, R.; Pol, H. E. Hulshoff; Nolen, W. A.; Kahn, R. S.; van Haren, N. E. M.

    Background. The risk of developing bipolar disorder (BD) has been linked to structural brain abnormalities. The degree to which genes and environment influence the association of BD with cortical surface area remains to be elucidated. In this twin study, genetic and environmental contributions to

  12. Longitudinal data on cortical thickness before and after working memory training

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    Claudia Metzler-Baddeley

    2016-06-01

    Full Text Available The data and supplementary information provided in this article relate to our research article “Task complexity and location specific changes of cortical thickness in executive and salience networks after working memory training” (Metzler-Baddeley et al., 2016 [1]. We provide cortical thickness and subcortical volume data derived from parieto-frontal cortical regions and the basal ganglia with the FreeSurfer longitudinal analyses stream (http://surfer.nmr.mgh.harvard.edu [2] before and after Cogmed working memory training (Cogmed and Cogmed Working Memory Training, 2012 [3]. This article also provides supplementary information to the research article, i.e., within-group comparisons between baseline and outcome cortical thickness and subcortical volume measures, between-group tests of performance changes in cognitive benchmark tests (www.cambridgebrainsciences.com [4], correlation analyses between performance changes in benchmark tests and training-related structural changes, correlation analyses between the time spent training and structural changes, a scatterplot of the relationship between cortical thickness measures derived from the occipital lobe as control region and the chronological order of the MRI sessions to assess potential scanner drift effects and a post-hoc vertex-wise whole brain analysis with FreeSurfer Qdec (https://surfer.nmr.mgh.harvard.edu/fswiki/Qdec [5].

  13. Longitudinal data on cortical thickness before and after working memory training.

    Science.gov (United States)

    Metzler-Baddeley, Claudia; Caeyenberghs, Karen; Foley, Sonya; Jones, Derek K

    2016-06-01

    The data and supplementary information provided in this article relate to our research article "Task complexity and location specific changes of cortical thickness in executive and salience networks after working memory training" (Metzler-Baddeley et al., 2016) [1]. We provide cortical thickness and subcortical volume data derived from parieto-frontal cortical regions and the basal ganglia with the FreeSurfer longitudinal analyses stream (http://surfer.nmr.mgh.harvard.edu [2]) before and after Cogmed working memory training (Cogmed and Cogmed Working Memory Training, 2012) [3]. This article also provides supplementary information to the research article, i.e., within-group comparisons between baseline and outcome cortical thickness and subcortical volume measures, between-group tests of performance changes in cognitive benchmark tests (www.cambridgebrainsciences.com [4]), correlation analyses between performance changes in benchmark tests and training-related structural changes, correlation analyses between the time spent training and structural changes, a scatterplot of the relationship between cortical thickness measures derived from the occipital lobe as control region and the chronological order of the MRI sessions to assess potential scanner drift effects and a post-hoc vertex-wise whole brain analysis with FreeSurfer Qdec (https://surfer.nmr.mgh.harvard.edu/fswiki/Qdec [5]).

  14. A CBCT atlas of buccal cortical bone thickness in interradicular spaces

    Science.gov (United States)

    Holmes, Patrick B.; Wolf, Bethany J.; Zhou, Jing

    2016-01-01

    Objective To provide a road map of buccal cortical bone thickness in interradicular locations where miniscrew implants are commonly placed. Materials and Methods Cone-beam computed tomography images from 100 study quadrants (50 maxillary and 50 mandibular) were studied. Cortical bone thickness was measured at the most mesial point, the midpoint, and the most distal point in interradicular areas from the canine to the first molar in both arches at 4 mm and 6 mm from the alveolar ridge. Indicator variables of whether the cortical bone thickness was thinner than 1 mm and thicker than 1.5 mm were constructed and analyzed in a general linear mixed model. Results Buccal cortical bone was significantly thinner at a point bisecting two teeth than the bone adjacent to the teeth (P 1.5 mm (50%) was in the mandible adjacent to the first molar (distal to the midpoint of the second premolar and first molar) at 6 mm from the alveolar crest. Conclusion Cortical bone thickness is significantly thinner centrally between two teeth than in the areas adjacent to the roots. PMID:25760885

  15. Cortical thickness, cortical surface area and subcortical volumes in schizophrenia and bipolar disorder patients with cannabis use.

    Science.gov (United States)

    Hartberg, Cecilie Bhandari; Lange, Elisabeth H; Lagerberg, Trine Vik; Haukvik, Unn K; Andreassen, Ole A; Melle, Ingrid; Agartz, Ingrid

    2018-01-01

    Cannabis is associated with increased risk for severe mental illness and is commonly used among individuals with schizophrenia or bipolar disorder. In this study we investigated associations between cannabis use and brain structures among patients with schizophrenia or bipolar disorders. Magnetic resonance imaging scans were obtained for 77 schizophrenia and 55 bipolar patients with a history of cannabis use (defined as lifetime use >10 times during one month or abuse/dependence), and 97 schizophrenia, 85 bipolar disorder patients and 277 healthy controls without any previous cannabis use. Cortical thickness, cortical surface area and subcortical volumes were compared between groups. Both hypothesis-driven region-of-interest analyses from 11 preselected brain regions in each hemisphere and exploratory point-by-point analyses were performed. We tested for diagnostic interactions and controlled for potential confounders. After controlling for confounders such as tobacco use and alcohol use disorders we found reduced cortical thickness in the caudal middle frontal gyrus compared to non-user patients and healthy controls. The findings were not significant when patients with co-morbid alcohol and illicit drug use were excluded from the analyses, but onset of cannabis use before illness onset was associated with cortical thinning in the caudal middle frontal gyrus. To conclude, we found no structural brain changes associated with cannabis use among patients with severe mental illness, but the findings indicate excess cortical thinning among those who use cannabis before illness onset. The present findings support the understanding that cannabis use is associated with limited brain effects in schizophrenia as well as bipolar disorder. Copyright © 2017 Elsevier B.V. and ECNP. All rights reserved.

  16. Cortical thickness maturation and duration of music training: health-promoting activities shape brain development.

    Science.gov (United States)

    Hudziak, James J; Albaugh, Matthew D; Ducharme, Simon; Karama, Sherif; Spottswood, Margaret; Crehan, Eileen; Evans, Alan C; Botteron, Kelly N

    2014-11-01

    To assess the extent to which playing a musical instrument is associated with cortical thickness development among healthy youths. Participants were part of the National Institutes of Health (NIH) Magnetic Resonance Imaging (MRI) Study of Normal Brain Development. This study followed a longitudinal design such that participants underwent MRI scanning and behavioral testing on up to 3 separate visits, occurring at 2-year intervals. MRI, IQ, and music training data were available for 232 youths (334 scans), ranging from 6 to 18 years of age. Cortical thickness was regressed against the number of years that each youth had played a musical instrument. Next, thickness was regressed against an "Age × Years of Playing" interaction term. Age, gender, total brain volume, and scanner were controlled for in analyses. Participant ID was entered as a random effect to account for within-person dependence. False discovery rate correction was applied (p ≤ .05). There was no association between thickness and years playing a musical instrument. The "Age × Years of Playing" interaction was associated with thickness in motor, premotor, and supplementary motor cortices, as well as prefrontal and parietal cortices. Follow-up analysis revealed that music training was associated with an increased rate of thickness maturation. Results were largely unchanged when IQ and handedness were included as covariates. Playing a musical instrument was associated with more rapid cortical thickness maturation within areas implicated in motor planning and coordination, visuospatial ability, and emotion and impulse regulation. However, given the quasi-experimental nature of this study, we cannot rule out the influence of confounding variables. Copyright © 2014 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

  17. Regional brain differences in cortical thickness, surface area and subcortical volume in individuals with Williams syndrome.

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    Shashwath A Meda

    Full Text Available Williams syndrome (WS is a rare genetic neurodevelopmental disorder characterized by increased non-social anxiety, sensitivity to sounds and hypersociability. Previous studies have reported contradictory findings with regard to regional brain variation in WS, relying on only one type of morphological measure (usually volume in each study. The present study aims to contribute to this body of literature and perhaps elucidate some of these discrepancies by examining concurrent measures of cortical thickness, surface area and subcortical volume between WS subjects and typically-developing (TD controls. High resolution MRI scans were obtained on 31 WS subjects and 50 typically developing control subjects. We derived quantitative regional estimates of cortical thickness, cortical surface area, and subcortical volume using FreeSurfer software. We evaluated between-group ROI differences while controlling for total intracranial volume. In post-hoc exploratory analyses within the WS group, we tested for correlations between regional brain variation and Beck Anxiety Inventory scores. Consistent with our hypothesis, we detected complex patterns of between-group cortical variation, which included lower surface area in combination with greater thickness in the following cortical regions: post central gyrus, cuneus, lateral orbitofrontal cortex and lingual gyrus. Additional cortical regions showed between-group differences in one (but not both morphological measures. Subcortical volume was lower in the basal ganglia and the hippocampus in WS versus TD controls. Exploratory correlations revealed that anxiety scores were negatively correlated with gray matter surface area in insula, OFC, rostral middle frontal, superior temporal and lingual gyrus. Our results were consistent with previous reports showing structural alterations in regions supporting the socio-affective and visuospatial impairments in WS. However, we also were able to effectively capture novel and

  18. Cortical thickness changes correlate with cognition changes after cognitive training: Evidence from a Chinese community study

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    Lijuan eJiang

    2016-05-01

    Full Text Available The aim of this study was to investigate whether changes in cortical thickness correlated with cognitive function changes in healthy older adults after receiving cognitive training interventions. Moreover, it also aimed to examine the differential impacts of a multi-domain and a single-domain cognitive training interventions. Longitudinal magnetic resonance imaging (MRI scanning was performed on participants 65 to 75 years of age using the Siemens 3.0 T Trio Tim with the MPRAGE sequence. The cortical thickness was determined using FreeSurfer software. Cognitive functioning was evaluated using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS. There were significant group × time interaction effects on the left supramarginal, the left frontal pole cortical regions; and a marginal significant group × time interaction effects on visuospatial/constructional and delayed memory scores. In a multi-domain cognitive training group, a number of cortical region changes were significantly positively correlated with changes in attention, delayed memory, and the total score, but significantly negatively correlated with changes in immediate memory and language scores. In the single-domain cognitive training group, some cortical region changes were significantly positively associated with changes in immediate memory, delayed memory, and the total score, while they were significantly negatively associated with changes in visuospatial/constructional, language, and attention scores. Overall, multi-domain cognitive training offered more advantages in visuospatial/constructional, attention, and delayed memory abilities, while single-domain cognitive training benefited immediate memory ability more effectively. These findings suggest that healthy older adults benefit more from the multi-domain cognitive training than single-domain cognitive training. Cognitive training has impacted on cortical thickness changes in healthy elderly

  19. Radiographic technique and brackets affect measurements of proximal enamel thickness on mandibular incisors

    NARCIS (Netherlands)

    Ang, Amy Giok Phing; Steegmans, Pauline Antoinette Josephine; Kerdijk, Wouter; Livas, Christos; Ren, Yijin

    2017-01-01

    Objective: To investigate the influence of radiographic film and tube positioning, the presence and the size of brackets on in vitro measurements of proximal enamel thickness of mandibular incisors on periapical radiographs aimed to aid planning of interproximal enamel reduction procedures in

  20. Effect of Cortical Bone Thickness on Detection of Intraosseous Lesions by Ultrasonography

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    Sadaf Adibi

    2015-01-01

    Full Text Available Background. Usefulness of ultrasound (US in detection of intrabony lesions has been showed. A cortical bone perforation or a very thin and intact cortical bone is prerequisite for this purpose. Objective. The current in vitro study was aimed at measuring the cut-off thickness of the overlying cortical bone which allows ultrasonic assessment of bony defects. Materials and Methods. 20 bovine scapula blocks were obtained. Samples were numbered from 1 to 20. In each sample, 5 artificial lesions were made. The lesions were made in order to increase the overlying bone thickness, from 0.1 mm in the first sample to 2 mm in the last one (with 0.1 mm interval. After that, the samples underwent ultrasound examinations by two practicing radiologists. Results. All five lesions in samples numbered 1 to 11 were detected as hypoechoic area. Cortical bone thickness more than 1.1 mm resulted in a failure in the detection of central lesions. Conclusion. We can conclude that neither bony perforation nor very thin cortical bones are needed to consider US to be an effective imaging technique in the evaluation of bony lesion.

  1. Positive Association of Video Game Playing with Left Frontal Cortical Thickness in Adolescents

    Science.gov (United States)

    Kühn, Simone; Lorenz, Robert; Banaschewski, Tobias; Barker, Gareth J.; Büchel, Christian; Conrod, Patricia J.; Flor, Herta; Garavan, Hugh; Ittermann, Bernd; Loth, Eva; Mann, Karl; Nees, Frauke; Artiges, Eric; Paus, Tomas; Rietschel, Marcella; Smolka, Michael N.; Ströhle, Andreas; Walaszek, Bernadetta; Schumann, Gunter; Heinz, Andreas; Gallinat, Jürgen

    2014-01-01

    Playing video games is a common recreational activity of adolescents. Recent research associated frequent video game playing with improvements in cognitive functions. Improvements in cognition have been related to grey matter changes in prefrontal cortex. However, a fine-grained analysis of human brain structure in relation to video gaming is lacking. In magnetic resonance imaging scans of 152 14-year old adolescents, FreeSurfer was used to estimate cortical thickness. Cortical thickness across the whole cortical surface was correlated with self-reported duration of video gaming (hours per week). A robust positive association between cortical thickness and video gaming duration was observed in left dorsolateral prefrontal cortex (DLPFC) and left frontal eye fields (FEFs). No regions showed cortical thinning in association with video gaming frequency. DLPFC is the core correlate of executive control and strategic planning which in turn are essential cognitive domains for successful video gaming. The FEFs are a key region involved in visuo-motor integration important for programming and execution of eye movements and allocation of visuo-spatial attention, processes engaged extensively in video games. The results may represent the biological basis of previously reported cognitive improvements due to video game play. Whether or not these results represent a-priori characteristics or consequences of video gaming should be studied in future longitudinal investigations. PMID:24633348

  2. Positive association of video game playing with left frontal cortical thickness in adolescents.

    Directory of Open Access Journals (Sweden)

    Simone Kühn

    Full Text Available Playing video games is a common recreational activity of adolescents. Recent research associated frequent video game playing with improvements in cognitive functions. Improvements in cognition have been related to grey matter changes in prefrontal cortex. However, a fine-grained analysis of human brain structure in relation to video gaming is lacking. In magnetic resonance imaging scans of 152 14-year old adolescents, FreeSurfer was used to estimate cortical thickness. Cortical thickness across the whole cortical surface was correlated with self-reported duration of video gaming (hours per week. A robust positive association between cortical thickness and video gaming duration was observed in left dorsolateral prefrontal cortex (DLPFC and left frontal eye fields (FEFs. No regions showed cortical thinning in association with video gaming frequency. DLPFC is the core correlate of executive control and strategic planning which in turn are essential cognitive domains for successful video gaming. The FEFs are a key region involved in visuo-motor integration important for programming and execution of eye movements and allocation of visuo-spatial attention, processes engaged extensively in video games. The results may represent the biological basis of previously reported cognitive improvements due to video game play. Whether or not these results represent a-priori characteristics or consequences of video gaming should be studied in future longitudinal investigations.

  3. A new method to determine cortical bone thickness in CT images using a hybrid approach of parametric profile representation and local adaptive thresholds: Accuracy results.

    Science.gov (United States)

    Museyko, Oleg; Gerner, Bastian; Engelke, Klaus

    2017-01-01

    Cortical bone is an important contributor to bone strength and is pivotal to understand the etiology of osteoporotic fractures and the specific mechanisms of antiosteoporotic treatment regimen. 3D computed tomography (CT) can be used to measure cortical thickness, density, and mass in the proximal femur, lumbar vertebrae, and distal forearm. However, the spatial resolution of clinical whole body CT scanners is limited by radiation exposure; partial volume artefacts severely impair the accurate assessment of cortical parameters, in particular in locations where the cortex is thin such as in the lumbar vertebral bodies or in the femoral neck. Model-based deconvolution approaches recover the cortical thickness by numerically deconvolving the image along 1D profiles using an estimated scanner point spread function (PSF) and a hypothesized uniform cortical bone mineral density (reference density). In this work we provide a new essentially analytical unique solution to the model-based cortex recovery problem using few characteristics of the measured profile and thus eliminate the non-linear optimization step for deconvolution. Also, the proposed approach allows to get rid of the PSF in the model and reduces sensitivity to errors in the reference density. Additionally, run-time and memory effective computation of cortical thickness was achieved with the help of a lookup table. The method accuracy and robustness was validated and compared to that of a deconvolution approach recently proposed for cortical bone and of the 50% relative threshold technique: in a simulated environment with noise and various error levels in the reference density and using CT acquisitions of the European Forearm Phantom (EFP II), a modification of a widely used anthropomorphic standard of cortical and trabecular bone compartments that was scanned with various scan protocols. Results of simulations and of phantom data analysis verified the following properties of the new method: 1) Robustness

  4. Brain volumes and regional cortical thickness in young females with anorexia nervosa.

    Science.gov (United States)

    Fuglset, Tone Seim; Endestad, Tor; Hilland, Eva; Bang, Lasse; Tamnes, Christian Krog; Landrø, Nils Inge; Rø, Øyvind

    2016-11-16

    Anorexia nervosa (AN) is a severe mental illness, with an unknown etiology. Magnetic resonance imaging studies show reduced brain volumes and cortical thickness in patients compared to healthy controls. However, findings are inconsistent, especially concerning the anatomical location and extent of the differences. The purpose of this study was to estimate and compare brain volumes and regional cortical thickness in young females with AN and healthy controls. Magnetic resonance imaging data was acquired from young females with anorexia nervosa (n = 23) and healthy controls (n = 28). Two different scanner sites were used. BMI varied from 13.5 to 20.7 within the patient group, and 11 patients had a BMI > 17.5. FreeSurfer was used to estimate brain volumes and regional cortical thickness. There were no differences between groups in total cerebral cortex volume, white matter volume, or lateral ventricle volume. There were also no volume differences in subcortical grey matter structures. However the results showed reduced cortical thickness bilaterally in the superior parietal gyrus, and in the right inferior parietal and superior frontal gyri. The functional significance of the findings is undetermined as the majority of the included patients was already partially weight-restored. We discuss whether these regions could be related to predisposing factors of the illness, or whether they are regions that are more vulnerable to starvation, malnutrition or associated processes in AN.

  5. Cortical thickness of planum temporale and pars opercularis in native language tone processing.

    Science.gov (United States)

    Schremm, Andrea; Novén, Mikael; Horne, Merle; Söderström, Pelle; van Westen, Danielle; Roll, Mikael

    2018-01-01

    The present study investigated the relationship between linguistic tone processing and cortical thickness of bilateral planum temporale (PT) and pars opercularis of the inferior frontal gyrus (IFGpo). Swedish tones on word stems function as cues to upcoming endings. Correlating structural brain imaging data with participants' response time patterns for suffixes, we found that thicker cortex in the left PT was associated with greater reliance on tones to anticipate upcoming inflections on real words. On inflected pseudoword stems, however, the cortical thickness of left IFGpo was associated with tone-suffix processing. Thus cortical thickness of the left PT might play a role in processing tones as part of stored representations for familiar speech segments, most likely when inflected forms are accessed as whole words. In the absence of stored representations, listeners might need to rely on morphosyntactic rules specifying tone-suffix associations, potentially facilitated by greater cortical thickness of left IFGpo. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Age of language learning shapes brain structure: a cortical thickness study of bilingual and monolingual individuals.

    Science.gov (United States)

    Klein, Denise; Mok, Kelvin; Chen, Jen-Kai; Watkins, Kate E

    2014-04-01

    We examined the effects of learning a second language (L2) on brain structure. Cortical thickness was measured in the MRI datasets of 22 monolinguals and 66 bilinguals. Some bilingual subjects had learned both languages simultaneously (0-3 years) while some had learned their L2 after achieving proficiency in their first language during either early (4-7 years) or late childhood (8-13 years). Later acquisition of L2 was associated with significantly thicker cortex in the left inferior frontal gyrus (IFG) and thinner cortex in the right IFG. These effects were seen in the group comparisons of monolinguals, simultaneous bilinguals and early and late bilinguals. Within the bilingual group, significant correlations between age of acquisition of L2 and cortical thickness were seen in the same regions: cortical thickness correlated with age of acquisition positively in the left IFG and negatively in the right IFG. Interestingly, the monolinguals and simultaneous bilinguals did not differ in cortical thickness in any region. Our results show that learning a second language after gaining proficiency in the first language modifies brain structure in an age-dependent manner whereas simultaneous acquisition of two languages has no additional effect on brain development. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Through Thick and Thin: a Need to Reconcile Contradictory Results on Trajectories in Human Cortical Development.

    Science.gov (United States)

    Walhovd, Kristine B; Fjell, Anders M; Giedd, Jay; Dale, Anders M; Brown, Timothy T

    2017-02-01

    Understanding how brain development normally proceeds is a premise of understanding neurodevelopmental disorders. This has sparked a wealth of magnetic resonance imaging (MRI) studies. Unfortunately, they are in marked disagreement on how the cerebral cortex matures. While cortical thickness increases for the first 8-9 years of life have repeatedly been reported, others find continuous cortical thinning from early childhood, at least from age 3 or 4 years. We review these inconsistencies, and discuss possible reasons, including the use of different scanners, recording parameters and analysis tools, and possible effects of variables such as head motion. When tested on the same subsample, 2 popular thickness estimation methods (CIVET and FreeSurfer) both yielded a continuous thickness decrease from 3 years. Importantly, MRI-derived measures of cortical development are merely our best current approximations, hence the term "apparent cortical thickness" may be preferable. We recommend strategies for reaching consensus in the field, including multimodal neuroimaging to measure phenomena using different techniques, for example, the use of T1/T2 ratio, and data sharing to allow replication across analysis methods. As neurodevelopmental origins of early- and late-onset disease are increasingly recognized, resolving inconsistencies in brain maturation trajectories is important. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  8. WNT16 influences bone mineral density, cortical bone thickness, bone strength, and osteoporotic fracture risk

    NARCIS (Netherlands)

    H.-F. Zheng (Hou-Feng); J.H. Tobias (Jon); E.L. Duncan (Emma); D.M. Evans (David); J. Eriksson (Joel); L. Paternoster (Lavinia); L.M. Yerges-Armstrong (Laura); T. Lehtimäki (Terho); U. Bergström (Ulrica); M. Kähönen (Mika); P.J. Leo (Paul); O. Raitakari (Olli); M. Laaksonen (Marika); G.C. Nicholson (Geoffrey); J. Viikari (Jorma); M. Ladouceur (Martin); L.-P. Lyytikäinen (Leo-Pekka); M.C. Medina-Gomez (Carolina); F. Rivadeneira Ramirez (Fernando); R.L. Prince (Richard); H. Sievanen (Harri); W.D. Leslie (William); D. Mellström (Dan); J.A. Eisman (John); S. Movérare-Skrtic (Sofia); D. Goltzman (David); G.E. Hanley (Gillian); G. Jones (Graeme); B. St Pourcain (Beate); Y. Xiao (Yanling); N.J. Timpson (Nicholas); G.D. Smith; I.R. Reid (Ian); S.M. Ring (Susan); P.N. Sambrook (Philip); M. Karlsson (Magnus); E.M. Dennison (Elaine); J.P. Kemp (John); P. Danoy (Patrick); I. Sayers (Ian); S.G. Wilson (Scott); M. Nethander (Maria); E.V. McCloskey (Eugene); L. Vandenput (Liesbeth); R. Eastell (Richard); T. Idzenga (Tim); T.D. Spector (Timothy); B.D. Mitchell (Braxton); E.A. Streeten (Elizabeth); R. Brommage (Robert); U. Pettersson-Kymmer (Ulrika); M.A. Brown (Matthew); C. Ohlsson (Claes); J.B. Richards (Brent); M. Lorentzon (Mattias)

    2012-01-01

    textabstractWe aimed to identify genetic variants associated with cortical bone thickness (CBT) and bone mineral density (BMD) by performing two separate genome-wide association study (GWAS) meta-analyses for CBT in 3 cohorts comprising 5,878 European subjects and for BMD in 5 cohorts comprising

  9. Online Learning for Classification of Alzheimer Disease based on Cortical Thickness and Hippocampal Shape Analysis.

    Science.gov (United States)

    Lee, Ga-Young; Kim, Jeonghun; Kim, Ju Han; Kim, Kiwoong; Seong, Joon-Kyung

    2014-01-01

    Mobile healthcare applications are becoming a growing trend. Also, the prevalence of dementia in modern society is showing a steady growing trend. Among degenerative brain diseases that cause dementia, Alzheimer disease (AD) is the most common. The purpose of this study was to identify AD patients using magnetic resonance imaging in the mobile environment. We propose an incremental classification for mobile healthcare systems. Our classification method is based on incremental learning for AD diagnosis and AD prediction using the cortical thickness data and hippocampus shape. We constructed a classifier based on principal component analysis and linear discriminant analysis. We performed initial learning and mobile subject classification. Initial learning is the group learning part in our server. Our smartphone agent implements the mobile classification and shows various results. With use of cortical thickness data analysis alone, the discrimination accuracy was 87.33% (sensitivity 96.49% and specificity 64.33%). When cortical thickness data and hippocampal shape were analyzed together, the achieved accuracy was 87.52% (sensitivity 96.79% and specificity 63.24%). In this paper, we presented a classification method based on online learning for AD diagnosis by employing both cortical thickness data and hippocampal shape analysis data. Our method was implemented on smartphone devices and discriminated AD patients for normal group.

  10. Insertion torque versus mechanical resistance of mini-implants inserted in different cortical thickness

    Science.gov (United States)

    Santos, Renata de Faria; Ruellas, Antonio Carlos de Oliveira; Fernandes, Daniel Jogaib; Elias, Carlos Nelson

    2014-01-01

    Objective This study aimed to measure insertion torque, tip mechanical resistance to fracture and transmucosal neck of mini-implants (MI) (Conexão Sistemas de PróteseT), as well as to analyze surface morphology. Methods Mechanical tests were carried out to measure the insertion torque of MIs in different cortical thicknesses, and tip mechanical resistance to fracture as well as transmucosal neck of MIs. Surface morphology was assessed by scanning electron microscopy (SEM) before and after the mechanical tests. Results Values of mechanical resistance to fracture (22.14 N.cm and 54.95 N.cm) were higher and statistically different (P 0.05) to torsional fracture in the tip of MI (22.14 N.cm) when 3 mm cortical thickness (16.11 N.cm) and dense bone (23.95 N.cm) were used. Torsional fracture of the transmucosal neck (54.95 N.cm) was higher and statistically different (P mini-implants tested presented adequate surface morphology. The resistance of mini-implants to fracture safely allows placement in 1 and 2-mm cortical thickness. However, in 3-mm cortical thickness and dense bones, pre-drilling with a bur is recommended before insertion. PMID:25162571

  11. Effects of Age and Symptomatology on Cortical Thickness in Autism Spectrum Disorders

    Science.gov (United States)

    Doyle-Thomas, Krissy A. R.; Duerden, Emma G.; Taylor, Margot J.; Lerch, Jason P.; Soorya, Latha V.; Wang, A. Ting; Fan, Jin; Hollander, Eric; Anagnostou, Evdokia

    2013-01-01

    Several brain regions show structural and functional abnormalities in individuals with autism spectrum disorders (ASD), but the developmental trajectory of abnormalities in these structures and how they may relate to social and communicative impairments are still unclear. We assessed the effects of age on cortical thickness in individuals with…

  12. Does cortical bone thickness in the last sacral vertebra differ among tail types in primates?

    Science.gov (United States)

    Nishimura, Abigail C; Russo, Gabrielle A

    2017-04-01

    The external morphology of the sacrum is demonstrably informative regarding tail type (i.e., tail presence/absence, length, and prehensility) in living and extinct primates. However, little research has focused on the relationship between tail type and internal sacral morphology, a potentially important source of functional information when fossil sacra are incomplete. Here, we determine if cortical bone cross-sectional thickness of the last sacral vertebral body differs among tail types in extant primates and can be used to reconstruct tail types in extinct primates. Cortical bone cross-sectional thickness in the last sacral vertebral body was measured from high-resolution CT scans belonging to 20 extant primate species (N = 72) assigned to tail type categories ("tailless," "nonprehensile short-tailed," "nonprehensile long-tailed," and "prehensile-tailed"). The extant dataset was then used to reconstruct the tail types for four extinct primate species. Tailless primates had significantly thinner cortical bone than tail-bearing primates. Nonprehensile short-tailed primates had significantly thinner cortical bone than nonprehensile long-tailed primates. Cortical bone cross-sectional thickness did not distinguish between prehensile-tailed and nonprehensile long-tailed taxa. Results are strongly influenced by phylogeny. Corroborating previous studies, Epipliopithecus vindobonensis was reconstructed as tailless, Archaeolemur edwardsi as long-tailed, Megaladapis grandidieri as nonprehensile short-tailed, and Palaeopropithecus kelyus as nonprehensile short-tailed or tailless. Results indicate that, in the context of phylogenetic clade, measures of cortical bone cross-sectional thickness can be used to allocate extinct primate species to tail type categories. © 2017 Wiley Periodicals, Inc.

  13. Variations in crestal cortical bone thickness at dental implant sites in different regions of the jawbone.

    Science.gov (United States)

    Ko, Yi-Chun; Huang, Heng-Li; Shen, Yen-Wen; Cai, Jyun-Yi; Fuh, Lih-Jyh; Hsu, Jui-Ting

    2017-06-01

    Dental implants have become reliable and predictable tools for treating missing teeth. The survival rate of dental implants is markedly influenced by the host bone quality and quantity of the jawbone. A better host bone provides higher initial stability of the dental implant, resulting in better osseointegration and a higher success rate. Host bone quality and quantity are determined by the crestal cortical bone thickness and inner cancellous bone density. The purpose of this study was to determine the crestal cortical bone thickness at dental implant sites in different regions of the jawbone through the use of dental cone-beam computed tomographic (CBCT) images. A total of 661 dental implant sites (81 in the anterior mandible, 122 in the anterior maxilla, 224 in the posterior mandible, and 234 in the posterior maxilla) were obtained from the jawbones of 173 humans. The data were subjected to statistical analysis to determine any correlation between crestal cortical bone thicknesses and jawbone regions using one-way analysis of variance with Tukey's post-test. The crestal cortical bone thicknesses at dental implant sites in the four regions decreased in the following order: posterior mandible (1.07 ± 0.47 mm, mean ± SD) >anterior mandible (0.99 ± 0.36 mm) >anterior maxilla (0.82 ± 0.30 mm) >posterior maxilla (0.75 ± 0.35 mm). The dental CBCT data demonstrate that crestal cortical bone thickness varies markedly between dental implant sites in the four regions of the jawbone. © 2017 Wiley Periodicals, Inc.

  14. A novel cortical thickness estimation method based on volumetric Laplace-Beltrami operator and heat kernel.

    Science.gov (United States)

    Wang, Gang; Zhang, Xiaofeng; Su, Qingtang; Shi, Jie; Caselli, Richard J; Wang, Yalin

    2015-05-01

    Cortical thickness estimation in magnetic resonance imaging (MRI) is an important technique for research on brain development and neurodegenerative diseases. This paper presents a heat kernel based cortical thickness estimation algorithm, which is driven by the graph spectrum and the heat kernel theory, to capture the gray matter geometry information from the in vivo brain magnetic resonance (MR) images. First, we construct a tetrahedral mesh that matches the MR images and reflects the inherent geometric characteristics. Second, the harmonic field is computed by the volumetric Laplace-Beltrami operator and the direction of the steamline is obtained by tracing the maximum heat transfer probability based on the heat kernel diffusion. Thereby we can calculate the cortical thickness information between the point on the pial and white matter surfaces. The new method relies on intrinsic brain geometry structure and the computation is robust and accurate. To validate our algorithm, we apply it to study the thickness differences associated with Alzheimer's disease (AD) and mild cognitive impairment (MCI) on the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset. Our preliminary experimental results on 151 subjects (51 AD, 45 MCI, 55 controls) show that the new algorithm may successfully detect statistically significant difference among patients of AD, MCI and healthy control subjects. Our computational framework is efficient and very general. It has the potential to be used for thickness estimation on any biological structures with clearly defined inner and outer surfaces. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Age effects on cortical thickness in young Down's syndrome subjects: a cross-sectional gender study

    Energy Technology Data Exchange (ETDEWEB)

    Romano, Andrea; Moraschi, Marta [San Raffaele Foundation Rome, Rehabilitation Facility Ceglie Messapica, Rome (Italy); Cornia, Riccardo; Stella, Giacomo [University of Modena and Reggio Emilia, Department of Education and Human Sciences, Emilia-Romagna (Italy); Bozzao, Alessandro; Gagliardo, Olga [University Sapienza, NESMOS, Department of Neuroradiology, S. Andrea Hospital, Rome (Italy); Chiacchiararelli, Laura [University Sapienza, Department of Medical Physics, S. Andrea Hospital, Rome (Italy); Iani, Cristina [University of Modena and Reggio Emilia, Department of Communication and Economy, Emilia-Romagna (Italy); Albertini, Giorgio [IRCSS San Raffaele Pisana, Department of Paediatrics, Rome (Italy); Pierallini, Alberto [IRCSS San Raffaele Pisana, Department of Radiology, Rome (Italy)

    2015-04-01

    The aim of this study was to determine differences in the characteristic pattern of age-related cortical thinning in men and women with Down's syndrome (DS) by means of MRI and automatic cortical thickness measurements and a cross-sectional design, in a large cohort of young subjects. Eighty-four subjects with DS, 30 females (11-35 years, mean age ± SD = 22.8 ± 5.9) and 54 males (11-35 years, mean age ± SD = 21.5 ± 6.5), were examined using a 1.5-T scanner. MRI-based quantification of cortical thickness was performed using FreeSurfer software package. For all subjects participating in the study, the Pearson product-moment correlation coefficient between age and mean cortical thickness values has been evaluated. A significant negative correlation between cortical thickness and age was found in female DS subjects, predominantly in frontal and parietal lobes, bilaterally. In male DS subjects, a significant negative correlation between cortical thickness and age was found in the right fronto-temporal lobes and cingulate regions. Whole brain mean cortical thickness values were significantly negative correlated with age only in female DS subjects. Females with Down's syndrome showed a strong correlation between cortical thickness and age, already in early age. We suggest that the cognitive impairment due to hormonal deficit in the postmenopausal period could be emphasized by the early structural decline of gray matter in female DS subjects. (orig.)

  16. Sex, age, and cognitive correlates of asymmetries in thickness of the cortical mantle across the life span

    DEFF Research Database (Denmark)

    Plessen, Kerstin J; Hugdahl, Kenneth; Bansal, Ravi

    2014-01-01

    lateral, dorsal, and mesial surfaces of the frontal lobe, extending into primary sensory, superior parietal, and anterior superior temporal cortices. A right > left asymmetry was present in the lateral, mesial, and dorsal surfaces of the posterior temporal, parietal, and occipital cortices, as well...... scattered along the mesial surface of the brain. Age significantly moderated asymmetry measures in the inferior sensorimotor, inferior parietal, posterior temporal, and inferior occipital cortices. The age × asymmetry interaction derived from a steeper decline in cortical thickness with age in the right......We assessed the correlations of age, sex, and cognitive performance with measures of asymmetry in cortical thickness on high-resolution MRIs in 215 healthy human children and adults, 7-59 years of age. A left > right asymmetry in thickness of the cortical mantle was present throughout the entire...

  17. Interactive Effects of Dehydroepiandrosterone and Testosterone on Cortical Thickness during Early Brain Development

    Science.gov (United States)

    Nguyen, Tuong-Vi; McCracken, James T.; Ducharme, Simon; Cropp, Brett F.; Botteron, Kelly N.; Evans, Alan C.

    2013-01-01

    Humans and the great apes are the only species demonstrated to exhibit adrenarche, a key endocrine event associated with prepubertal increases in the adrenal production of androgens, most significantly dehydroepiandrosterone (DHEA) and to a certain degree testosterone. Adrenarche also coincides with the emergence of the prosocial and neurobehavioral skills of middle childhood and may therefore represent a human-specific stage of development. Both DHEA and testosterone have been reported in animal and in vitro studies to enhance neuronal survival and programmed cell death depending on the timing, dose, and hormonal context involved, and to potentially compete for the same signaling pathways. Yet no extant brain-hormone studies have examined the interaction between DHEA- and testosterone-related cortical maturation in humans. Here, we used linear mixed models to examine changes in cortical thickness associated with salivary DHEA and testosterone levels in a longitudinal sample of developmentally healthy children and adolescents 4–22 years old. DHEA levels were associated with increases in cortical thickness of the left dorsolateral prefrontal cortex, right temporoparietal junction, right premotor and right entorhinal cortex between the ages of 4–13 years, a period marked by the androgenic changes of adrenarche. There was also an interaction between DHEA and testosterone on cortical thickness of the right cingulate cortex and occipital pole that was most significant in prepubertal subjects. DHEA and testosterone appear to interact and modulate the complex process of cortical maturation during middle childhood, consistent with evidence at the molecular level of fast/nongenomic and slow/genomic or conversion-based mechanisms underlying androgen-related brain development. PMID:23804104

  18. Cortical Thickness and Subcortical Gray Matter Volume in Pediatric Anxiety Disorders.

    Science.gov (United States)

    Gold, Andrea L; Steuber, Elizabeth R; White, Lauren K; Pacheco, Jennifer; Sachs, Jessica F; Pagliaccio, David; Berman, Erin; Leibenluft, Ellen; Pine, Daniel S

    2017-11-01

    Perturbations in the prefrontal cortex (PFC), hippocampus, and amygdala are implicated in the development of anxiety disorders. However, most structural neuroimaging studies of patients with anxiety disorders utilize adult samples, and the few studies in youths examine small samples, primarily with volume-based measures. This study tested the hypothesis that cortical thickness of PFC regions and gray matter volume of the hippocampus and amygdala differ between pediatric anxiety disorder patients and healthy volunteers (HVs). High-resolution 3-Tesla T1-weighted MRI scans were acquired in 151 youths (75 anxious, 76 HV; ages 8-18). Analyses tested associations of brain structure with anxiety diagnosis and severity across both groups, as well as response to cognitive-behavioral therapy in a subset of 53 patients. Cortical thickness was evaluated both within an a priori PFC mask (small-volume corrected) and using an exploratory whole-brain-corrected (panxiety treatment response but not baseline anxiety.

  19. Association of Optic Radiation Integrity with Cortical Thickness in Children with Anisometropic Amblyopia.

    Science.gov (United States)

    Qi, Shun; Mu, Yun-Feng; Cui, Long-Biao; Li, Rong; Shi, Mei; Liu, Ying; Xu, Jun-Qing; Zhang, Jian; Yang, Jian; Yin, Hong

    2016-02-01

    Previous studies have indicated regional abnormalities of both gray and white matter in amblyopia. However, alterations of cortical thickness associated with changes in white matter integrity have rarely been reported. In this study, structural magnetic resonance imaging and diffusion tensor imaging (DTI) data were obtained from 15 children with anisometropic amblyopia and 15 age- and gender-matched children with normal sight. Combining DTI and surface-based morphometry, we examined a potential linkage between disrupted white matter integrity and altered cortical thickness. The fractional anisotropy (FA) values in the optic radiations (ORs) of children with anisometropic amblyopia were lower than in controls (P amblyopia. These findings indicate that developmental changes occur simultaneously in the OR and visual cortex in amblyopia, and provide key information on complex damage of brain networks in anisometropic amblyopia. Our results also support the hypothesis that the pathogenesis of anisometropic amblyopia is neurodevelopmental.

  20. Increased Executive Functioning, Attention, and Cortical Thickness in White-Collar Criminals

    Science.gov (United States)

    Raine, Adrian; Laufer, William S.; Yang, Yaling; Narr, Katherine L.; Thompson, Paul; Toga, Arthur W.

    2011-01-01

    Very little is known on white collar crime and how it differs to other forms of offending. This study tests the hypothesis that white collar criminals have better executive functioning, enhanced information processing, and structural brain superiorities compared to offender controls. Using a case-control design, executive functioning, orienting, and cortical thickness was assessed in 21 white collar criminals matched with 21 controls on age, gender, ethnicity, and general level of criminal offending. White collar criminals had significantly better executive functioning, increased electrodermal orienting, increased arousal, and increased cortical gray matter thickness in the ventromedial prefrontal cortex, inferior frontal gyrus, somatosensory cortex, and the temporal-parietal junction compared to controls. Results, while initial, constitute the first findings on neurobiological characteristics of white-collar criminals It is hypothesized that white collar criminals have information-processing and brain superiorities that give them an advantage in perpetrating criminal offenses in occupational settings. PMID:22002326

  1. Intramedullary cortical bone strut improves the cyclic stability of osteoporotic proximal humeral fractures.

    Science.gov (United States)

    Hsiao, Chih-Kun; Tsai, Yi-Jung; Yen, Cheng-Yo; Lee, Cheng-Hung; Yang, Teng-Yao; Tu, Yuan-Kun

    2017-02-02

    Proximal humeral fractures treated with locking plate can fail due to varus collapse, especially in osteoporotic bone with medial cortex comminution. The use of an intramedullary strut together with locking plate fixation may strengthen fixation and provide additional medial support to prevent the varus malalignment. This study biomechanically investigates the influence of an intramedullary cortical bone strut on the cyclic stability of proximal humeral fractures stabilized by locking plate fixation in a cadaver model. Ten cadaveric humeri were divided into two groups statistically matched for bone density. Each specimen was osteotomized with 10 mm gap at the surgical neck. The non-augmented group stabilized with locking plate alone; in the augmented group, a locking plate was used combined with an intramedullary cortical bone strut. The strut was retrograded into the subchondral bone, and three humeral head screws were inserted into the strut to form a plate-screw-strut mechanism. The cyclic axial load was performed to 450 N for 6000 cycles and then loaded to failure. Construct stiffness, cyclic loading behavior and failure strength were analyzed to identify differences between groups. The augmented constructs were significantly stiffer than the non-augmented constructs during cycling. On average, the maximum displacements at 6000 cycles for non-augmented and augmented groups were 3.10 ± 0.75 mm and 1.7 ± 0.65 mm (p = 0.01), respectively. The mean peak-to-peak (inter cycle) displacement at 6000 cycles was about 2 times lower for the augmented group (1.36 ± 0.68 mm vs. 2.86 ± 0.51 mm). All specimens showed varus collapse combined with loss of screw fixation of the humeral head. The failure load of the augmented group was increased by 2.0 (SD = 0.41) times compared with the non-augmented group (p proximal humeral fractures fixed with a locked plate under cyclic loading, especially in bone with poor quality. This work is based

  2. Radiation-induced abnormal cortical thickness in patients with nasopharyngeal carcinoma after radiotherapy.

    Science.gov (United States)

    Lin, Jiabao; Lv, Xiaofei; Niu, Meiqi; Liu, Lizhi; Chen, Jun; Xie, Fei; Zhong, Miao; Qiu, Shijun; Li, Li; Huang, Ruiwang

    2017-01-01

    Conventional MRI studies showed that radiation-induced brain necrosis in patients with nasopharyngeal carcinoma (NPC) in years after radiotherapy (RT) could involve brain gray matter (GM) and impair brain function. However, it is still unclear the radiation-induced brain morphological changes in NPC patients with normal-appearing GM in the early period after RT. In this study, we acquired high-resolution brain structural MRI data from three groups of patients, 22 before radiotherapy (pre-RT) NPC patients with newly diagnosed but not yet medically treated, 22 NPC patients in the early-delayed stage after radiotherapy (post-RT-ED), and 20 NPC patients in the late-delayed stage after radiotherapy (post-RT-LD), and then analyzed the radiation-induced cortical thickness alteration in NPC patients after RT. Using a vertex-wise surface-based morphometry (SBM) approach, we detected significantly decreased cortical thickness in the precentral gyrus (PreCG) in the post-RT-ED group compared to the pre-RT group. And the post-RT-LD group showed significantly increased cortical thickness in widespread brain regions, including the bilateral inferior parietal, left isthmus of the cingulate, left bank of the superior temporal sulcus and left lateral occipital regions, compared to the pre-RT group, and in the bilateral PreCG compared to the post-RT-ED group. Similar analysis with ROI-wise SBM method also found the consistent results. These results indicated that radiation-induced brain injury mainly occurred in the post-RT-LD group and the cortical thickness alterations after RT were dynamic in different periods. Our findings may reflect the pathogenesis of radiation-induced brain injury in NPC patients with normal-appearing GM and an early intervention is necessary for protecting GM during RT.

  3. Serotonin Signaling Modulates the Effects of Familial Risk for Depression on Cortical Thickness

    Science.gov (United States)

    Bansal, Ravi; Peterson, Bradley S.; Gingrich, Jay; Hao, Xuejun; Odgerel, Zagaa; Warner, Virginia; Wickramaratne, Priya J.; Talati, Ardesheer; Ansorge, Mark; Brown, Alan S.; Sourander, Andre; Weissman, Myrna M.

    2016-01-01

    Depression is a highly familial and a heritable illness that is more prevalent in the biological offspring of the depressed individuals than in the general population. In a 3-generation, 30-year, longitudinal study of individuals at either a high(HR) or a low(LR) familial risk for depression, we previously showed cortical thinning in the right hemisphere was an endophenotype for the familial risk. In this study, we assessed whether the effects of familial risk were modulated by the serotonin-transporter-linked polymorphic region (5-HTTLPR). We measured cortical thickness using MRI of the brain and associated it with 5-HTTLPR polymorphism in 76 HR and 53 LR individuals. We studied the effects of genotype and gene-by-risk interaction on cortical thickness while controlling for the confounding effects of age and gender, and for the familial relatedness by applying a variance component model with random effects for genotype. The results showed significant effects of gene-by-risk interaction on thickness: The “s” allele was associated with thinner cortex in the LR individuals whereas with thicker cortex in the HR individuals. The opposing gene effects across the two risk groups were likely due to either epistatic effects and/or differing modulation of the neural plasticity by the altered 5-HT signaling in utero. PMID:26774425

  4. Thickness of extensor tendons at the proximal intersection: sonographic measurements in asymptomatic volunteers.

    Science.gov (United States)

    Christiaanse, Ernst; Jager, Tjeerd; Lenchik, Leon; Buls, Nico; Van Hedent, Eddy; De Maeseneer, Michel

    2014-12-01

    An important sign of proximal intersection syndrome is thickening of the tendons at the area where the first extensor compartment tendons cross over the second compartment. Normal values for the thickness of the tendons have not been reported. Our purpose was to measure the thickness of the tendons with sonography at the level of the intersection in healthy volunteers and assess differences between men and women, dominant and nondominant sides, and different tendons. Forty-one asymptomatic volunteers (25 women and 16 men) were examined by 2 radiologists experienced in musculoskeletal sonography. The thickness of the tendons in the first and second compartments was measured at their intersection at standardized proximal and distal levels. Descriptive statistics were obtained. Differences between men and women, dominant and nondominant sides, and different tendons were evaluated by a Student t test. The 95% confidence intervals for measurements of superimposed tendon groups varied between 0.30 and 0.40 cm in women and between 0.36 and 0.48 cm in men. There were no statistically significant differences in comparisons of the different tendon groups (P > .05). There were statistically significant differences (P measurement) and extensor carpi radialis brevis + extensor pollicis brevis (distal measurement). On comparison of dominant and nondominant sides, there were no statistically significant differences. Normal tendon thickness should be between 0.30 and 0.40 cm in women and 0.36 and 0.48 cm in men. A comparison between asymptomatic and symptomatic sides and proximal and distal measurements is recommended. © 2013 by the American Institute of Ultrasound in Medicine.

  5. Cortical thickness correlates of psychotic experiences: examining the effect of season of birth using a genetically informative design.

    Science.gov (United States)

    Córdova-Palomera, A; Alemany, S; Falcón, C; Bargalló, N; Goldberg, X; Crespo-Facorro, B; Nenadic, I; Fañanás, L

    2014-09-01

    Season of birth has been shown to influence risk for several neuropsychiatric diseases. Furthermore, it has been suggested that season of birth modifies a number of brain morphological traits. Since cortical thickness alterations have been reported across some levels of the psychosis-spectrum, this study was aimed at i) assessing the scarcely explored relationship between cortical thickness and severity of subclinical psychotic experiences (PEs) in healthy subjects, and ii) evaluating the potential impact of season of birth in the preceding thickness-PEs relationship. As both PEs and brain cortical features are heritable, the current work used monozygotic twins to separately evaluate familial and unique environmental factors. High-resolution structural MRI scans of 48 twins (24 monozygotic pairs) were analyzed to estimate cortical thickness using FreeSurfer. They were then examined in relation to PEs, accounting for the effects of birth season; putative differential relationships between PEs and cortical thickness depending on season of birth were also tested. Current results support previous findings indicative of cortical thickening in healthy individuals with high psychometrically assessed psychosis scores, probably in line with theories of compensatory aspects of brain features in non-clinical populations. Additionally, they suggest distinct patterns of cortical thickness-PEs relationships depending on birth seasonality. Familial factors underlying the presence of PEs may drive these effects. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Cortical thickness and inattention/hyperactivity symptoms in young children: a population-based study.

    Science.gov (United States)

    Mous, S E; Muetzel, R L; El Marroun, H; Polderman, T J C; van der Lugt, A; Jaddoe, V W; Hofman, A; Verhulst, F C; Tiemeier, H; Posthuma, D; White, T

    2014-11-01

    While many neuroimaging studies have investigated the neurobiological basis of attention deficit hyperactivity disorder (ADHD), few have studied the neurobiology of attention problems in the general population. The ability to pay attention falls along a continuum within the population, with children with ADHD at one extreme of the spectrum and, therefore, a dimensional perspective of evaluating attention problems has an added value to the existing literature. Our goal was to investigate the relationship between cortical thickness and inattention and hyperactivity symptoms in a large population of young children. This study is embedded within the Generation R Study and includes 6- to 8-year-old children (n = 444) with parent-reported attention and hyperactivity measures and high-resolution structural imaging data. We investigated the relationship between cortical thickness across the entire brain and the Child Behavior Checklist Attention Deficit Hyperactivity Problems score. We found that greater attention problems and hyperactivity were associated with a thinner right and left postcentral gyrus. When correcting for potential confounding factors and multiple testing, these associations remained significant. In a large, population-based sample we showed that young (6- to 8-year-old) children who show more attention problems and hyperactivity have a thinner cortex in the region of the right and left postcentral gyrus. The postcentral gyrus, being the primary somatosensory cortex, reaches its peak growth early in development. Therefore, the thinner cortex in this region may reflect either a deviation in cortical maturation or a failure to reach the same peak cortical thickness compared with children without attention or hyperactivity problems.

  7. Patterns of cortical thickness associated with impulse control disorders in Parkinson's disease.

    Science.gov (United States)

    Biundo, Roberta; Weis, Luca; Facchini, Silvia; Formento-Dojot, Patrizia; Vallelunga, Annamaria; Pilleri, Manuela; Weintraub, Daniel; Antonini, Angelo

    2015-04-15

    Previous functional neuroimaging studies in Parkinson's disease (PD) patients with impulse control disorders (ICDs) demonstrated dysfunction of the reward network, although the extent of anatomical changes is unclear. The aim of this study was to measure brain cortical thickness and subcortical volumes, and to assess their relationship with presence and severity of symptoms, in PD patients with and without ICDs. We studied 110 PD patients (N=58 with ICDs) and 33 healthy controls (all negative for ICDs) who underwent an extensive neurological, neuropsychological, and behavioral assessment as well as structural 1.5 Tesla magnetic resonance imaging (MRI). Between-group differences in brain cortical thickness and subcortical volumes, assessed with the FreeSurfer 5.1 tool, were analyzed. In patients with ICDs, we found significant cortical thinning in fronto-striatal circuitry, specifically in the right superior orbitofrontal, left rostral middle frontal, bilateral caudal middle frontal region, and corpus callosum, as well as volume reduction in the right accumbens and increase in the left amygdala. Finally, we observed a positive association relationship between severity of impulsive symptoms and left rostral middle frontal, inferior parietal, and supramarginal areas. These results support the involvement of both reward and response inhibition networks in PD patients with ICDs. Moreover, their severity is associated with alterations in brain regions linked with reward and top-down control networks. Increased understanding of the mechanisms underlying impulsive and compulsive behaviors might help improve therapeutic strategies for these important disorders. © 2015 International Parkinson and Movement Disorder Society.

  8. Type-2 diabetes mellitus reduces cortical thickness and decreases oxidative metabolism in sensorimotor regions after stroke.

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    Ferris, Jennifer K; Peters, Sue; Brown, Katlyn E; Tourigny, Katherine; Boyd, Lara A

    2017-01-01

    Individuals with type-2 diabetes mellitus experience poor motor outcomes after ischemic stroke. Recent research suggests that type-2 diabetes adversely impacts neuronal integrity and function, yet little work has considered how these neuronal changes affect sensorimotor outcomes after stroke. Here, we considered how type-2 diabetes impacted the structural and metabolic function of the sensorimotor cortex after stroke using volumetric magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). We hypothesized that the combination of chronic stroke and type-2 diabetes would negatively impact the integrity of sensorimotor cortex as compared to individuals with chronic stroke alone. Compared to stroke alone, individuals with stroke and diabetes had lower cortical thickness bilaterally in the primary somatosensory cortex, and primary and secondary motor cortices. Individuals with stroke and diabetes also showed reduced creatine levels bilaterally in the sensorimotor cortex. Contralesional primary and secondary motor cortex thicknesses were negatively related to sensorimotor outcomes in the paretic upper-limb in the stroke and diabetes group such that those with thinner primary and secondary motor cortices had better motor function. These data suggest that type-2 diabetes alters cerebral energy metabolism, and is associated with thinning of sensorimotor cortex after stroke. These factors may influence motor outcomes after stroke.

  9. Dance Experience and Associations with Cortical Gray Matter Thickness in the Aging Population

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    Shai Porat

    2016-10-01

    Full Text Available Introduction: We investigated the effect dance experience may have on cortical gray matter thickness and cognitive performance in elderly participants with and without mild cognitive impairment (MCI. Methods: 39 cognitively normal and 48 MCI elderly participants completed a questionnaire regarding their lifetime experience with music, dance, and song. Participants identified themselves as either dancers or nondancers. All participants received structural 1.5-tesla MRI scans and detailed clinical and neuropsychological evaluations. An advanced 3D cortical mapping technique was then applied to calculate cortical thickness. Results: Despite having a trend-level significantly thinner cortex, dancers performed better in cognitive tasks involving learning and memory, such as the California Verbal Learning Test-II (CVLT-II short delay free recall (p = 0.004, the CVLT-II long delay free recall (p = 0.003, and the CVLT-II learning over trials 1-5 (p = 0.001. Discussion: Together, these results suggest that dance may result in an enhancement of cognitive reserve in aging, which may help avert or delay MCI.

  10. LOGISMOS-B for primates: primate cortical surface reconstruction and thickness measurement

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    Oguz, Ipek; Styner, Martin; Sanchez, Mar; Shi, Yundi; Sonka, Milan

    2015-03-01

    Cortical thickness and surface area are important morphological measures with implications for many psychiatric and neurological conditions. Automated segmentation and reconstruction of the cortical surface from 3D MRI scans is challenging due to the variable anatomy of the cortex and its highly complex geometry. While many methods exist for this task in the context of the human brain, these methods are typically not readily applicable to the primate brain. We propose an innovative approach based on our recently proposed human cortical reconstruction algorithm, LOGISMOS-B, and the Laplace-based thickness measurement method. Quantitative evaluation of our approach was performed based on a dataset of T1- and T2-weighted MRI scans from 12-month-old macaques where labeling by our anatomical experts was used as independent standard. In this dataset, LOGISMOS-B has an average signed surface error of 0.01 +/- 0.03mm and an unsigned surface error of 0.42 +/- 0.03mm over the whole brain. Excluding the rather problematic temporal pole region further improves unsigned surface distance to 0.34 +/- 0.03mm. This high level of accuracy reached by our algorithm even in this challenging developmental dataset illustrates its robustness and its potential for primate brain studies.

  11. Quantitative evaluation of maxillary alveolar cortical bone thickness and density using computed tomography imaging.

    Science.gov (United States)

    Ohiomoba, Henry; Sonis, Andrew; Yansane, Alfa; Friedland, Bernard

    2017-01-01

    Primary stability is essential to the success of orthodontic mini-implants (OMIs) and heavily depends on the mechanical retention between OMIs and their supporting bone. Alveolar cortical bone commonly serves as the supporting bone for OMIs during treatment. The purposes of this study were to characterize alveolar cortical bone thickness and density in the maxilla and to explore patient factors that may significantly affect these bone properties. Sixty medical computed tomography scans of the maxilla were analyzed from a selected sample of patients seen at the Radiology Department of Boston Children's Hospital. Interradicular alveolar bone thickness and density were measured at 2, 4, 6, and 8 mm from the buccal and palatal alveolar bone crests using the Synapse 3D software (version 4.1; FUJIFILM Medical Systems USA, Stamford, Conn). Analyses were conducted with STATA /1C (version 12.0 for Windows; StataCorp, College Station, Tex) using multivariate mixed-effects regression models and paired t tests. Mean age and body mass index of the study sample were 17.88 years and 22.94 kg/m2, respectively. Cortical bone density and thickness significantly increased from the coronal (2 mm) to the apical (8 mm) regions of the alveolar bone (P bone was thickest (1 mm) and densest (1395 Hounsfield units) between the first and second molars. On the palatal side, the thickest bone (1.15 mm) was found between the canine and first premolar; it was similarly densest (1406 Hounsfield units) between the first premolar and canine, and between the first premolar and second premolar interradicular bones. On average, palatal cortical bone was thicker and denser compared with buccal; this difference was statistically significant (P maxillary region showing the greatest difference. Female subjects have significantly denser bone compared with male subjects; however, sex is not significantly associated with bone thickness. Body mass index and age are positively associated with bone

  12. A new method to determine cortical bone thickness in CT images using a hybrid approach of parametric profile representation and local adaptive thresholds: Accuracy results.

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    Oleg Museyko

    Full Text Available Cortical bone is an important contributor to bone strength and is pivotal to understand the etiology of osteoporotic fractures and the specific mechanisms of antiosteoporotic treatment regimen. 3D computed tomography (CT can be used to measure cortical thickness, density, and mass in the proximal femur, lumbar vertebrae, and distal forearm. However, the spatial resolution of clinical whole body CT scanners is limited by radiation exposure; partial volume artefacts severely impair the accurate assessment of cortical parameters, in particular in locations where the cortex is thin such as in the lumbar vertebral bodies or in the femoral neck.Model-based deconvolution approaches recover the cortical thickness by numerically deconvolving the image along 1D profiles using an estimated scanner point spread function (PSF and a hypothesized uniform cortical bone mineral density (reference density. In this work we provide a new essentially analytical unique solution to the model-based cortex recovery problem using few characteristics of the measured profile and thus eliminate the non-linear optimization step for deconvolution. Also, the proposed approach allows to get rid of the PSF in the model and reduces sensitivity to errors in the reference density. Additionally, run-time and memory effective computation of cortical thickness was achieved with the help of a lookup table.The method accuracy and robustness was validated and compared to that of a deconvolution approach recently proposed for cortical bone and of the 50% relative threshold technique: in a simulated environment with noise and various error levels in the reference density and using CT acquisitions of the European Forearm Phantom (EFP II, a modification of a widely used anthropomorphic standard of cortical and trabecular bone compartments that was scanned with various scan protocols.Results of simulations and of phantom data analysis verified the following properties of the new method: 1

  13. Bone turnover markers are associated with higher cortical porosity, thinner cortices, and larger size of the proximal femur and non-vertebral fractures.

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    Shigdel, Rajesh; Osima, Marit; Ahmed, Luai A; Joakimsen, Ragnar M; Eriksen, Erik F; Zebaze, Roger; Bjørnerem, Åshild

    2015-12-01

    Bone turnover markers (BTM) predict bone loss and fragility fracture. Although cortical porosity and cortical thinning are important determinants of bone strength, the relationship between BTM and cortical porosity has, however, remained elusive. We therefore wanted to examine the relationship of BTM with cortical porosity and risk of non-vertebral fracture. In 211 postmenopausal women aged 54-94 years with non-vertebral fractures and 232 age-matched fracture-free controls from the Tromsø Study, Norway, we quantified femoral neck areal bone mineral density (FN aBMD), femoral subtrochanteric bone architecture, and assessed serum levels of procollagen type I N-terminal propeptide (PINP) and C-terminal cross-linking telopeptide of type I collagen (CTX). Fracture cases exhibited higher PINP and CTX levels, lower FN aBMD, larger total and medullary cross-sectional area (CSA), thinner cortices, and higher cortical porosity of the femoral subtrochanter than controls (p≤0.01). Each SD increment in PINP and CTX was associated with 0.21-0.26 SD lower total volumetric BMD, 0.10-0.14 SD larger total CSA, 0.14-0.18 SD larger medullary CSA, 0.13-0.18 SD thinner cortices, and 0.27-0.33 SD higher porosity of the total cortex, compact cortex, and transitional zone (all p≤0.01). Moreover, each SD of higher PINP and CTX was associated with increased odds for fracture after adjustment for age, height, and weight (ORs 1.49; 95% CI, 1.20-1.85 and OR 1.22; 95% CI, 1.00-1.49, both pfracture after accounting for FN aBMD, cortical porosity or cortical thickness (OR ranging from 1.31 to 1.39, p ranging from 0.005 to 0.028). In summary, increased BTM levels are associated with higher cortical porosity, thinner cortices, larger bone size and higher odds for fracture. We infer that this is produced by increased periosteal apposition, intracortical and endocortical remodeling; and that these changes in bone architecture are predisposing to fracture. Copyright © 2015 Elsevier Inc. All

  14. Reproducibility of brain-cognition relationships using three cortical surface-based protocols: An exhaustive analysis based on cortical thickness.

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    Martínez, Kenia; Madsen, Sarah K; Joshi, Anand A; Joshi, Shantanu H; Román, Francisco J; Villalon-Reina, Julio; Burgaleta, Miguel; Karama, Sherif; Janssen, Joost; Marinetto, Eugenio; Desco, Manuel; Thompson, Paul M; Colom, Roberto

    2015-08-01

    People differ in their cognitive functioning. This variability has been exhaustively examined at the behavioral, neural and genetic level to uncover the mechanisms by which some individuals are more cognitively efficient than others. Studies investigating the neural underpinnings of interindividual differences in cognition aim to establish a reliable nexus between functional/structural properties of a given brain network and higher order cognitive performance. However, these studies have produced inconsistent results, which might be partly attributed to methodological variations. In the current study, 82 healthy young participants underwent MRI scanning and completed a comprehensive cognitive battery including measurements of fluid, crystallized, and spatial intelligence, along with working memory capacity/executive updating, controlled attention, and processing speed. The cognitive scores were obtained by confirmatory factor analyses. T1 -weighted images were processed using three different surface-based morphometry (SBM) pipelines, varying in their degree of user intervention, for obtaining measures of cortical thickness (CT) across the brain surface. Distribution and variability of CT and CT-cognition relationships were systematically compared across pipelines and between two cognitively/demographically matched samples to overcome potential sources of variability affecting the reproducibility of findings. We demonstrated that estimation of CT was not consistent across methods. In addition, among SBM methods, there was considerable variation in the spatial pattern of CT-cognition relationships. Finally, within each SBM method, results did not replicate in matched subsamples. © 2015 Wiley Periodicals, Inc.

  15. Cortical Thickness, Surface Area and Subcortical Volume Differentially Contribute to Cognitive Heterogeneity in Parkinson's Disease.

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    Niels J H M Gerrits

    Full Text Available Parkinson's disease (PD is often associated with cognitive deficits, although their severity varies considerably between patients. Recently, we used voxel-based morphometry (VBM to show that individual differences in gray matter (GM volume relate to cognitive heterogeneity in PD. VBM does, however, not differentiate between cortical thickness (CTh and surface area (SA, which might be independently affected in PD. We therefore re-analyzed our cohort using the surface-based method FreeSurfer, and investigated (i CTh, SA, and (subcortical GM volume differences between 93 PD patients and 45 matched controls, and (ii the relation between these structural measures and cognitive performance on six neuropsychological tasks within the PD group. We found cortical thinning in PD patients in the left pericalcarine gyrus, extending to cuneus, precuneus and lingual areas and left inferior parietal cortex, bilateral rostral middle frontal cortex, and right cuneus, and increased cortical surface area in the left pars triangularis. Within the PD group, we found negative correlations between (i CTh of occipital areas and performance on a verbal memory task, (ii SA and volume of the frontal cortex and visuospatial memory performance, and, (iii volume of the right thalamus and scores on two verbal fluency tasks. Our primary findings illustrate that i CTh and SA are differentially affected in PD, and ii VBM and FreeSurfer yield non-overlapping results in an identical dataset. We argue that this discrepancy is due to technical differences and the subtlety of the PD-related structural changes.

  16. Reduced cortical thickness and increased surface area in antisocial personality disorder.

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    Jiang, Weixiong; Li, Gang; Liu, Huasheng; Shi, Feng; Wang, Tao; Shen, Celina; Shen, Hui; Lee, Seong-Whan; Hu, Dewen; Wang, Wei; Shen, Dinggang

    2016-11-19

    Antisocial personality disorder (ASPD), one of whose characteristics is high impulsivity, is of great interest in the field of brain structure and function. However, little is known about possible impairments in the cortical anatomy in ASPD, in terms of cortical thickness (CTh) and surface area (SA), as well as their possible relationship with impulsivity. In this neuroimaging study, we first investigated the changes of CTh and SA in ASPD patients, in comparison to those of healthy controls, and then performed correlation analyses between these measures and the ability of impulse control. We found that ASPD patients showed thinner cortex while larger SA in several specific brain regions, i.e., bilateral superior frontal gyrus (SFG), orbitofrontal and triangularis, insula cortex, precuneus, middle frontal gyrus (MFG), middle temporal gyrus (MTG), and left bank of superior temporal sulcus (STS). In addition, we also found that the ability of impulse control was positively correlated with CTh in the SFG, MFG, orbitofrontal cortex (OFC), pars triangularis, superior temporal gyrus (STG), and insula cortex. To our knowledge, this study is the first to reveal simultaneous changes in CTh and SA in ASPD, as well as their relationship with impulsivity. These cortical structural changes may introduce uncontrolled and callous behavioral characteristic in ASPD patients, and these potential biomarkers may be very helpful in understanding the pathomechanism of ASPD. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  17. Cortical Thickness and Microstructural White Matter Changes Detect Amnestic Mild Cognitive Impairment.

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    Wang, Zan; Dai, Zhengjia; Shu, Hao; Liu, Duan; Guo, Qihao; He, Yong; Zhang, Zhijun

    2017-01-01

    Both the apolipoprotein E (APOE) ɛ4 allele and amnestic mild cognitive impairment (aMCI) are considered to be risk factors for Alzheimer's disease (AD). The primary aim of this study was to determine whether the aMCI-related abnormality in gray matter (GM) cortical thickness and white matter (WM) tracts integrity would be modified by the APOE genotype. A total of 146 older adults, including 64 aMCI patients (28 ɛ4 carriers and 36 non-carriers) and 82 healthy controls (39 ɛ4 carriers and 43 non-carriers), underwent a standardized clinical interview, neuropsychological battery assessment, and multi-modal brain magnetic resonance imaging scans. Compared with control subjects, the patients with aMCI showed significantly reduced cortical thickness bilaterally in the parahippocampal gyrus and disrupted WM integrity in the limbic tracts (e.g., increased mean diffusivity in the right parahippocampal cingulum and bilateral uncinate fasciculus). However, no significant main effects of the APOE genotype and diagnosis-by-genotype interaction on GM thickness and WM integrity were observed. Further, diffusivity measures of the limbic WM tracts were significantly correlated with the parahippocampal atrophy in aMCI. Importantly, the parahippocampal thickness and diffusivity measures of the limbic WM tracts were significantly correlated with the cognitive performance (i.e., episodic memory Z score) in patients with aMCI. These results demonstrate that WM microstructural disruptions in the limbic tracts are present at the early stage of AD in an APOE-independent manner; and this degeneration may occur progressively, in parallel with parahippocampal atrophy, and may specifically contribute to early initial impairment in episodic memory.

  18. Value of renal cortical thickness as a predictor of renal function impairment in chronic renal disease patients

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    Samia Rafael Yamashita

    2015-02-01

    Full Text Available Objective: To determine the presence of linear relationship between renal cortical thickness, bipolar length, and parenchymal thickness in chronic kidney disease patients presenting with different estimated glomerular filtration rates (GFRs and to assess the reproducibility of these measurements using ultrasonography. Materials and Methods: Ultrasonography was performed in 54 chronic renal failure patients. The scans were performed by two independent and blinded radiologists. The estimated GFR was calculated using the Cockcroft-Gault equation. Interobserver agreement was calculated and a linear correlation coefficient (r was determined in order to establish the relationship between the different renal measurements and estimated GFR. Results: The correlation between GFR and measurements of renal cortical thickness, bipolar length, and parenchymal thickness was, respectively, moderate (r = 0.478; p < 0.001, poor (r = 0.380; p = 0.004, and poor (r = 0.277; p = 0.116. The interobserver agreement was considered excellent (0.754 for measurements of cortical thickness and bipolar length (0.833, and satisfactory for parenchymal thickness (0.523. Conclusion: The interobserver reproducibility for renal measurements obtained was good. A moderate correlation was observed between estimated GFR and cortical thickness, but bipolar length and parenchymal thickness were poorly correlated.

  19. Allostatic Load Is Linked to Cortical Thickness Changes Depending on Body-Weight Status

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    Jonatan Ottino-González

    2017-12-01

    Full Text Available Objective: Overweight (body mass index or BMI ≥ 25 kg/m2 and stress interact with each other in complex ways. Overweight promotes chronic low-inflammation states, while stress is known to mediate caloric intake. Both conditions are linked to several avoidable health problems and to cognitive decline, brain atrophy, and dementia. Since it was proposed as a framework for the onset of mental illness, the allostatic load model has received increasing attention. Although changes in health and cognition related to overweight and stress are well-documented separately, the association between allostatic load and brain integrity has not been addressed in depth, especially among overweight subjects.Method: Thirty-four healthy overweight-to-obese and 29 lean adults underwent blood testing, neuropsychological examination, and magnetic resonance imaging to assess the relationship between cortical thickness and allostatic load, represented as an index of 15 biomarkers (this is, systolic and diastolic arterial tension, glycated hemoglobin, glucose, creatinine, total cholesterol, HDL and LDL cholesterol, triglycerides, c-reactive protein, interleukin-6, insulin, cortisol, fibrinogen, and leptin.Results: Allostatic load indexes showed widespread positive and negative significant correlations (p < 0.01 with cortical thickness values depending on body-weight status.Conclusion: The increase of allostatic load is linked to changes in the gray matter composition of regions monitoring behavior, sensory-reward processing, and general cognitive function.

  20. Beta-amyloid and Cortical Thickness Reveal Racial Disparities in Preclinical Alzheimer's Disease

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    Ian M. McDonough

    2017-01-01

    Full Text Available African Americans are two to four times more likely to develop dementia as Non-Hispanic Whites. This increased risk among African Americans represents a critical health disparity that affects nearly 43 million Americans. The present study tested the hypothesis that older African Americans with elevated beta-amyloid would show greater neurodegeneration (smaller hippocampal volumes and decreased cortical thickness than older Non-Hispanic Whites with elevated beta-amyloid. Data from the Harvard Aging Brain Study (HABS were used to form a group of older African Americans and two matched groups of Non-Hispanic White adults. Amyloid-positive African Americans had decreased cortical thickness in most of the Alzheimer's disease (AD signature regions compared with amyloid-positive Non-Hispanic Whites. This factor was negatively correlated with age and white matter hypointensities. Using support vector regression, we also found some evidence that African Americans have an older “brain age” than Non-Hispanic Whites. These findings suggest that African Americans might be more susceptible to factors causing neurodegeneration, which then might accelerate the rate of a diagnosis of AD.

  1. Neuroanatomical correlates of tinnitus revealed by cortical thickness analysis and diffusion tensor imaging

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    Aldhafeeri, Faten M. [The University of Liverpool, Department of Medical Imaging, School of Health Sciences, Liverpool (United Kingdom); King Khalid General Hospital, Ministry of Health, Radiology Department, Hafral-batin (Saudi Arabia); Mackenzie, Ian; Kay, Tony [Aintree University Hospitals NHS Foundation Trust, Liverpool (United Kingdom); Alghamdi, Jamaan [The University of Liverpool, Department of Medical Imaging, School of Health Sciences, Liverpool (United Kingdom); King Abdul Aziz University, Physics Department, Faculty of Sciences, Jeddah (Saudi Arabia); Sluming, Vanessa [The University of Liverpool, Department of Medical Imaging, School of Health Sciences, Liverpool (United Kingdom); Magnetic Resonance and Image Analysis Research Centre, Liverpool (United Kingdom)

    2012-08-15

    Tinnitus is a poorly understood auditory perception of sound in the absence of external stimuli. Convergent evidence proposes that tinnitus perception involves brain structural alterations as part of its pathophysiology. The aim of this study is to investigate the structural brain changes that might be associated with tinnitus-related stress and negative emotions. Using high-resolution magnetic resonance imaging and diffusion tensor imaging, we investigated grey matter and white matter (WM) alterations by estimating cortical thickness measures, fractional anisotropy and mean diffusivity in 14 tinnitus subjects and 14 age- and sex-matched non-tinnitus subjects. Significant cortical thickness reductions were found in the prefrontal cortex (PFC), temporal lobe and limbic system in tinnitus subjects compared to non-tinnitus subjects. Tinnitus sufferers were found to have disrupted WM integrity in tracts involving connectivity of the PFC, temporal lobe, thalamus and limbic system. Our results suggest that such neural changes may represent neural origins for tinnitus or consequences of tinnitus and its associations. (orig.)

  2. Cortical thickness changes in patients with Parkinson's disease and impulse control disorders.

    Science.gov (United States)

    Tessitore, Alessandro; Santangelo, Gabriella; De Micco, Rosa; Vitale, Carmine; Giordano, Alfonso; Raimo, Simona; Corbo, Daniele; Amboni, Marianna; Barone, Paolo; Tedeschi, Gioacchino

    2016-03-01

    To investigate gray matter (GM) and cortical thickness (CTh) changes in patients with Parkinson's disease (PD) with and without Impulse Control Disorders (ICDs). Fifteen patients with PD with ICDs (ICD+), 15 patients with PD without ICDs (ICD-) and 24 age and sex-matched healthy controls (HCs) were enrolled in the study. Patients were screened for ICDs by the Minnesota Impulsive Disorders Interview (MIDI) and underwent an extensive neuropsychological evaluation. Whole brain structural imaging was performed on a 3T GE MR scanner. Surface-based investigation of CTh was carried out by using Freesurfer Software. We also used voxel-based morphometry to investigate the pattern of GM atrophy. The voxel-wise analysis of the regional differences in CTh revealed that ICD+ patients showed a statistically significant (p<0.01 FDR) thicker cortex when compared to both ICD- patients and HCs in the anterior cingulate (ACC) and orbitofrontal (OFC) cortices. Moreover, cortical thickness abnormalities were positively correlated with ICD severity (p<0.05 FDR). VBM data did not reveal any statistically significant differences in local GM. Our results demonstrate that ICD+ patients have an increased CTh in limbic regions when compared with ICD- patients at the same disease stage and with an equal daily levodopa equivalent dose. These corticometric changes may play a role in the lack of inhibition of compulsive behaviors. The presence of such structural abnormalities may result from a synergistic effect of dopaminergic therapy in patients with a pre-existing vulnerability to develop an abnormal behavioral response to external stimuli. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Bisphosphonates improve trabecular bone mass and normalize cortical thickness in ovariectomized, osteoblast connexin43 deficient mice.

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    Watkins, Marcus P; Norris, Jin Yi; Grimston, Susan K; Zhang, Xiaowen; Phipps, Roger J; Ebetino, Frank H; Civitelli, Roberto

    2012-10-01

    The gap junction protein, connexin43 (Cx43) controls both bone formation and osteoclastogenesis via osteoblasts and/or osteocytes. Cx43 has also been proposed to mediate an anti-apoptotic effect of bisphosphonates, potent inhibitors of bone resorption. We studied whether bisphosphonates are effective in protecting mice with a conditional Cx43 gene deletion in osteoblasts and osteocytes (cKO) from the consequences of ovariectomy on bone mass and strength. Ovariectomy resulted in rapid loss of trabecular bone followed by a slight recovery in wild type (WT) mice, and a similar degree of trabecular bone loss, albeit slightly delayed, occurred in cKO mice. Treatment with either risedronate (20 μg/kg) or alendronate (40 μg/kg) prevented ovariectomy-induced bone loss in both genotypes. In basal conditions, bones of cKO mice have larger marrow area, higher endocortical osteoclast number, and lower cortical thickness and strength relative to WT. Ovariectomy increased endocortical osteoclast number in WT but not in cKO mice. Both bisphosphonates prevented these increases in WT mice, and normalized endocortical osteoclast number, cortical thickness and bone strength in cKO mice. Thus, lack of osteoblast/osteocyte Cx43 does not alter bisphosphonate action on bone mass and strength in estrogen deficiency. These results support the notion that one of the main functions of Cx43 in cortical bone is to restrain osteoblast and/or osteocytes from inducing osteoclastogenesis at the endocortical surface. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Effects of cross-sex hormone treatment on cortical thickness in transsexual individuals.

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    Zubiaurre-Elorza, Leire; Junque, Carme; Gómez-Gil, Esther; Guillamon, Antonio

    2014-05-01

    Untreated transsexuals have a brain cortical phenotype. Cross-sex hormone treatments are used to masculinize or feminize the bodies of female-to-male (FtMs) or male-to-female (MtFs) transsexuals, respectively. A longitudinal design was conducted to investigate the effects of treatments on brain cortical thickness (CTh) of FtMs and MtFs. This study investigated 15 female-to-male (FtMs) and 14 male-to-female (MtFs) transsexuals prior and during at least six months of cross-sex hormone therapy treatment. Brain MRI imaging was performed in a 3-Tesla TIM-TRIO Siemens scanner. T1-weighted images were analyzed with FreeSurfer software to obtain CTh as well as subcortical volumetric values. Changes in brain CTh thickness and volumetry associated to changes in hormonal levels due to cross-sex hormone therapy. After testosterone treatment, FtMs showed increases of CTh bilaterally in the postcentral gyrus and unilaterally in the inferior parietal, lingual, pericalcarine, and supramarginal areas of the left hemisphere and the rostral middle frontal and the cuneus region of the right hemisphere. There was a significant positive correlation between the serum testosterone and free testosterone index changes and CTh changes in parieto-temporo-occipital regions. In contrast, MtFs, after estrogens and antiandrogens treatment, showed a general decrease in CTh and subcortical volumetric measures and an increase in the volume of the ventricles. Testosterone therapy increases CTh in FtMs. Thickening in cortical regions is associated to changes in testosterone levels. Estrogens and antiandrogens therapy in MtFs is associated to a decrease in the CTh that consequently induces an enlargement of the ventricular system. © 2014 International Society for Sexual Medicine.

  5. The Importance of Aging in Gray Matter Changes Within Tinnitus Patients Shown in Cortical Thickness, Surface Area and Volume.

    Science.gov (United States)

    Yoo, Hye Bin; De Ridder, Dirk; Vanneste, Sven

    2016-11-01

    Aging and sensorineural hearing loss are known to be involved in the development of chronic tinnitus. This study explores the structural changes of gray matter using surface base methods and focuses more specifically on changes in cortical thickness in 127 tinnitus patients. The linear relationships between cortical thickness and behavioral measures including aging, tinnitus loudness, tinnitus duration, tinnitus distress, and hearing loss were analyzed. Three dimensional T1-weighted MR images were acquired and cortical gray matter volumes were segmented using FreeSurfer on Talairach space. The results showed that cortical thickness and volume are negatively correlated to age in widespread regions of frontal cortices, and positively to bilateral entorhinal cortex and left rostral anterior cingulate cortex. The cortical thickness changes related to hearing loss overlap with those related to normal aging. The gray matter volumes of bilateral amygdalae, hippocampi, nuclei accumbens, and thalami are all significantly negatively correlated to age. Tinnitus-related distress level and subjective loudness were negatively correlated only to the thalamic volume. The results suggest that the primary factor of long-term structural changes in chronic tinnitus patients is age and age related hearing loss, rather than hearing loss per se. Tinnitus related factors such as subjective tinnitus loudness, tinnitus duration, and the level of chronic tinnitus related distress were not correlated to important morphometric changes in this study.

  6. Correlation Between the Intima-Media Thickness of the Proximal and Distal Common Carotids

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    Roelke, Leonard Hermann, E-mail: leonardhr@terra.com.br; Rodrigues, Sergio Lamego [Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Lotufo, Paulo Andrade [Universidade de São Paulo, São Paulo, SP (Brazil); Mill, Jose Geraldo [Universidade Federal do Espírito Santo, Vitória, ES (Brazil)

    2013-09-15

    Increased IMT (intima-media thickness) in carotids is used as an early atherosclerosis marker and to evaluate the risk of cardiovascular problems. Ultrasound is used in the evaluation because it is accessible and low cost. Measurements for different carotid regions are described. To compare the proximal and distal region IMTs for the bilateral common carotid and guide its use in clinical practice. The IMT was measured in the proximal and distal common carotid arteries of 798 individuals (35-74 years old) of both genders using high-resolution ultrasound. Pearson's correlation coefficient was used to establish associations. The analyses were initially performed for the entire sample as well as subgroups with IMT <0.90 mm (49% of the sample) and ≥0.90 mm for at least one measurement site. The statistical significance was p < 0.05. The correlations investigated were significant. In the group with an IMT <0.90 mm, the correlations were between 0.44 and 0.62. In the subgroup with an IMT ≥0.90 mm, the correlations were significantly reduced to between 0.20 and 0.40. The data suggest that the IMT is more uniform along the carotid during early development and tends develop focally as it progresses. Therefore, in clinical evaluations of patients, the common carotid length should be investigated bilaterally to better use the available software and discern the IMT.

  7. Changes in cortical thickness in 6-year-old children open their mind to a global vision of the world.

    Science.gov (United States)

    Poirel, Nicolas; Leroux, Elise; Pineau, Arlette; Houdé, Olivier; Simon, Grégory

    2014-01-01

    Even if objectively presented with similar visual stimuli, children younger than 6 years of age exhibit a strong attraction to local visual information (e.g., the trees), whereas children older than 6 years of age, similar to adults, exhibit a visual bias toward global information (e.g., the forest). Here, we studied the cortical thickness changes that underlie this bias shift from local to global visual information. Two groups, matched for age, gender, and handedness, were formed from a total of 30 children who were 6 years old, and both groups performed a traditional global/local visual task. The first group presented a local visual bias, and the other group presented a global visual bias. The results indicated that, compared with the local visual bias group, children with a global visual bias exhibited (1) decreased cortical thickness in the bilateral occipital regions and (2) increased cortical thickness in the left frontoparietal regions. These findings constitute the first structural study that supports the view that both synaptic pruning (i.e., decreased cortical thickness) and expansion mechanisms (i.e., increased cortical thickness) cooccur to allow healthy children to develop a global perception of the visual world.

  8. Changes in Cortical Thickness in 6-Year-Old Children Open Their Mind to a Global Vision of the World

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    Nicolas Poirel

    2014-01-01

    Full Text Available Even if objectively presented with similar visual stimuli, children younger than 6 years of age exhibit a strong attraction to local visual information (e.g., the trees, whereas children older than 6 years of age, similar to adults, exhibit a visual bias toward global information (e.g., the forest. Here, we studied the cortical thickness changes that underlie this bias shift from local to global visual information. Two groups, matched for age, gender, and handedness, were formed from a total of 30 children who were 6 years old, and both groups performed a traditional global/local visual task. The first group presented a local visual bias, and the other group presented a global visual bias. The results indicated that, compared with the local visual bias group, children with a global visual bias exhibited (1 decreased cortical thickness in the bilateral occipital regions and (2 increased cortical thickness in the left frontoparietal regions. These findings constitute the first structural study that supports the view that both synaptic pruning (i.e., decreased cortical thickness and expansion mechanisms (i.e., increased cortical thickness cooccur to allow healthy children to develop a global perception of the visual world.

  9. Right frontal pole cortical thickness and executive functioning in children with traumatic brain injury: the impact on social problems.

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    Levan, Ashley; Black, Garrett; Mietchen, Jonathan; Baxter, Leslie; Brock Kirwan, C; Gale, Shawn D

    2016-12-01

    Cognitive and social outcomes may be negatively affected in children with a history of traumatic brain injury (TBI). We hypothesized that executive function would mediate the association between right frontal pole cortical thickness and problematic social behaviors. Child participants with a history of TBI were recruited from inpatient admissions for long-term follow-up (n = 23; average age = 12.8, average time post-injury =3.2 years). Three measures of executive function, the Trail Making Test, verbal fluency test, and the Conners' Continuous Performance Test-Second edition (CPT-II), were administered to each participant while caregivers completed the Childhood Behavior Checklist (CBCL). All participants underwent brain magnetic resonance imaging following cognitive testing. Regression analysis demonstrated right frontal pole cortical thickness significantly predicted social problems. Measures of executive functioning also significantly predicted social problems; however, the mediation model testing whether executive function mediated the relationship between cortical thickness and social problems was not statistically significant. Right frontal pole cortical thickness and omission errors on the CPT-II predicted Social Problems on the CBCL. Results did not indicate that the association between cortical thickness and social problems was mediated by executive function.

  10. Combined estimation of thickness and velocities using ultrasound guided waves: a pioneering study on in vitro cortical bone samples.

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    Foiret, Josquin; Minonzio, Jean-Gabriel; Chappard, Christine; Talmant, Maryline; Laugier, Pascal

    2014-09-01

    This paper reports for the first time on inverse estimation of several bone properties from guided-wave measurements in human bone samples. Previously, related approaches have focused on ultrasonic estimation of a single bone property at a time. The method is based on two steps: the multi-Lamb mode response is analyzed using the singular value decomposition signal processing method recently introduced in the field, then an identification procedure is run to find thickness and anisotropic elastic properties of the considered specimen. Prior to the measurements on bone, the method is validated on cortical bone-mimicking phantoms. The repeatability and the trueness of the estimated parameters on bone-mimicking phantoms were found around a few percent. Estimation of cortical thickness on bone samples was in good agreement with cortical thickness derived from high-resolution peripheral quantitative computed tomography data analysis of the samples.

  11. Cortical thickness, surface area and volume measures in Parkinson's disease, multiple system atrophy and progressive supranuclear palsy.

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    Amanda Worker

    Full Text Available Parkinson's disease (PD, Multiple System Atrophy (MSA and Progressive Supranuclear Palsy (PSP are neurodegenerative diseases that can be difficult to distinguish clinically. The objective of the current study was to use surface-based analysis techniques to assess cortical thickness, surface area and grey matter volume to identify unique morphological patterns of cortical atrophy in PD, MSA and PSP and to relate these patterns of change to disease duration and clinical features.High resolution 3D T1-weighted MRI volumes were acquired from 14 PD patients, 18 MSA, 14 PSP and 19 healthy control participants. Cortical thickness, surface area and volume analyses were carried out using the automated surface-based analysis package FreeSurfer (version 5.1.0. Measures of disease severity and duration were assessed for correlation with cortical morphometric changes in each clinical group.Results show that in PSP, widespread cortical thinning and volume loss occurs within the frontal lobe, particularly the superior frontal gyrus. In addition, PSP patients also displayed increased surface area in the pericalcarine. In comparison, PD and MSA did not display significant changes in cortical morphology.These results demonstrate that patients with clinically established PSP exhibit distinct patterns of cortical atrophy, particularly affecting the frontal lobe. These results could be used in the future to develop a useful clinical application of MRI to distinguish PSP patients from PD and MSA patients.

  12. A longitudinal study: changes in cortical thickness and surface area during pubertal maturation.

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    Megan M Herting

    Full Text Available Sex hormones have been shown to contribute to the organization and function of the brain during puberty and adolescence. Moreover, it has been suggested that distinct hormone changes in girls versus boys may contribute to the emergence of sex differences in internalizing and externalizing behavior during adolescence. In the current longitudinal study, the influence of within-subject changes in puberty (physical and hormonal on cortical thickness and surface area was examined across a 2-year span, while controlling for age. Greater increases in Tanner Stage predicted less superior frontal thinning and decreases in precuneus surface area in both sexes. Significant Tanner Stage and sex interactions were also seen, with less right superior temporal thinning in girls but not boys, as well as greater decreases in the right bank of the superior temporal sulcus surface area in boys compared to girls. In addition, within-subject changes in testosterone over the 2-year follow-up period were found to relate to decreases in middle superior frontal surface area in boys, but increases in surface area in girls. Lastly, larger increases in estradiol in girls predicted greater middle temporal lobe thinning. These results show that within-subject physical and hormonal markers of puberty relate to region and sex-specific changes in cortical development across adolescence.

  13. Focal Cortical Thickness Correlates of Exceptional Memory Training in Vedic Priests

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    Giridhar Padmanabhan Kalamangalam

    2014-10-01

    Full Text Available The capacity for semantic memory – the ability to acquire and store knowledge of the world - is highly developed in the human brain. In particular, semantic memory assimilated through an auditory route may be a uniquely human capacity. One method of obtaining neurobiological insight into auditory semantic memory mechanisms is through the study of experts. In this work, we study a group of Hindu Vedic priests, whose religious training requires the memorization of vast tracts of scriptural texts through an oral tradition, recalled spontaneously during a lifetime of subsequent spiritual practice. We demonstrate focal increases of cortical thickness in the dominant prefrontal lobe and non-dominant temporal lobe in Vedic priests, in comparison to a group of matched controls. The findings are relevant to current hypotheses regarding cognitive processes underlying storage and recall of long-term declarative memory.

  14. Cortical Thickness and White Matter Integrity are Associated with CTG Expansion Size in Myotonic Dystrophy Type I.

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    Yoo, Woo Kyoung; Park, Yoon Ghil; Choi, Young Chul; Kim, Sun Mi

    2017-07-01

    Myotonic dystrophy type 1 (DM1) is characterized by progressive muscular weakness with symptoms caused by involvement of the brain. The aim of this study was to delineate global changes in cortical thickness and white matter integrity in patients with DM1, compared to age-matched healthy controls, and in brain areas highly correlated with CTG repeat size. Cortical thickness and white matter integrity were compared in nine adult DM1 patients and age matched healthy controls using T1-weighted and diffusion tensor imaging. The patients' intelligence quotient (IQ) and CTG repeat size were measured in each individual. Cortical thickness was significantly reduced in the frontal, temporal, and occipital cortices, while tract-based spatial statistics showed decreased diffusion metrics in widespread areas, including the bilateral orbitofrontal, anterior frontal, insular, external capsule, and occipital cortices in DM1 patients, compared to controls. Additionally, thickness was negatively correlated with the number of CTG repeats in those areas. White matter integrity was negatively correlated with CTG repeats in the left entorhinal, anterior corona radiata, orbitofrontal, and lateral occipital areas. No statistically significant correlation was found between IQ scores and the size of CTG repeats. Our results suggest that DM1 is associated with wide distributions of network changes in both gray and white matter. Some of areas related to cognition showed significant correlations with CTG repeats.

  15. Right frontal pole cortical thickness and social competence in children with chronic traumatic brain injury: cognitive proficiency as a mediator.

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    Levan, Ashley; Baxter, Leslie; Kirwan, C Brock; Black, Garrett; Gale, Shawn D

    2015-01-01

    To examine the association between right frontal pole cortical thickness, social competence, and cognitive proficiency in children participants with a history of chronic traumatic brain injury (TBI). Twenty-three children (65% male; M age = 12.8 years, SD = 2.3 years) at least 1 year post-injury (M = 3.3 years, SD = 1.7 years) were evaluated with the Cognitive Proficiency Index (CPI) from the Wechsler Intelligence Scale for Children, 4th Edition, and their caregiver completed the Child Behavior Checklist. Social competence was evaluated with the Social Competence and Social Problems subscales from the Child Behavior Checklist. Right frontal pole cortical thickness was calculated via FreeSurfer from high-resolution 3-dimensional T1 magnetic resonance imaging scans. Direct effect of right frontal pole cortical thickness on social competence was significant (β = 14.09, SE = 4.6, P Right frontal pole cortical thickness significantly predicted CPI (β = 18.44, SE = 4.9, P right frontal lobe cortical integrity and social competence in pediatric participants with chronic TBI may be mediated through cognitive proficiency.

  16. Structural alteration of the dorsal visual network in DLB patients with visual hallucinations: a cortical thickness MRI study.

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    Stefano Delli Pizzi

    Full Text Available Visual hallucinations (VH represent one of the core features in discriminating dementia with Lewy bodies (DLB from Alzheimer's Disease (AD. Previous studies reported that in DLB patients functional alterations of the parieto-occipital regions were correlated with the presence of VH. The aim of our study was to assess whether morphological changes in specific cortical regions of DLB could be related to the presence and severity of VH. We performed a cortical thickness analysis on magnetic resonance imaging data in a cohort including 18 DLB patients, 15 AD patients and 14 healthy control subjects. Relatively to DLB group, correlation analysis between the cortical thickness and the Neuropsychiatric Inventory (NPI hallucination item scores was also performed. Cortical thickness was reduced bilaterally in DLB compared to controls in the pericalcarine and lingual gyri, cuneus, precuneus, superior parietal gyrus. Cortical thinning was found bilaterally in AD compared to controls in temporal cortex including the superior and middle temporal gyrus, part of inferior temporal cortex, temporal pole and insula. Inferior parietal and supramarginal gyri were also affected bilaterally in AD as compared to controls. The comparison between DLB and AD evidenced cortical thinning in DLB group in the right posterior regions including superior parietal gyrus, precuneus, cuneus, pericalcarine and lingual gyri. Furthermore, the correlation analysis between cortical thickness and NPI hallucination item scores showed that the structural alteration in the dorsal visual regions including superior parietal gyrus and precuneus closely correlated with the occurrence and severity of VH. We suggest that structural changes in key regions of the dorsal visual network may play a crucial role in the physiopathology of VH in DLB patients.

  17. Correlation between the thickness of the crestal and buccolingual cortical bone at varying depths and implant stability quotients.

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    Kanthanat Chatvaratthana

    Full Text Available Resonance frequency analysis (RFA is clinically used in dentistry to access the stiffness of dental implants in surrounding bone. However, the clear advantages and disadvantages of this method are still inconclusive. The aim of this study was to investigate and compare implant stability quotient (ISQ values obtained from RFA with parameters obtained from a cone beam computed tomography (CBCT scan of the same region.Nineteen implants (Conelog were inserted in the posterior maxillary and mandibular partially edentulous regions of 16 patients. At the time of implant placement, the ISQ values were obtained using RFA (Osstell. CBCT was used to measure the thickness of the crestal, cortical, buccolingual cortical, and cancellous bone at 3, 6, and 9 mm below the crestal bone level, as indicated by radiographic markers. The ratio of the thickness of the cortical to cancellous bone at varying depths was also calculated and classified into 4 groups (Group 1-4.There was a strong correlation between the crestal cortical bone thickness and ISQ values (P<0.001. The thickness of the buccolingual cortical bone and ratio of the cortical to cancellous bone thickness at 3 mm were significantly related to the ISQ (P = 0.018 and P = 0.034, respectively. Furthermore, the ISQs in Group 1 were the highest compared with those in Group 2 and Group 3, whereas the CBCT parameters at 6 and 9 mm did not have any specific correlation with the ISQ values.This study showed that the ISQ values obtained from RFA highly correlated with the quantity and quality of bone 3 mm below the crestal bone level. The correlation between the ISQ and bone surrounding the implant site was dependent on the depth of measurement. Therefore, RFA can help to predict the marginal bone level, as confirmed in this study.

  18. Effect of Filtration and Thickness of Cross-Sections of Cone Beam Computed Tomography Images on Detection of Proximal Caries.

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    Abdinian, Mehrdad; Nazeri, Rahman; Ghaiour, Marzieh

    2017-07-01

    When a patient has cone beam computed tomography (CBCT) images based on the treatment plan, it is possible to use these images for evaluation of caries, and there is no need for new radiographs, according to the "as low as reasonably achievable" (ALARA) principle. The aim of this study was to determine the effect of filtration and thickness of CBCT cross-sections on detection of proximal caries. In this in-vitro study, 100 teeth were placed in the dental sockets of a dry skull, and were fixed in normal proximal contacts. CBCT images were taken and were evaluated by two observers on the panoramic view at 1-, 3- and 5-mm-thick cross-sections, with the use of filtrations 0, 1 and 2. Afterwards, the samples were sectioned and underwent a histological evaluation. McNemar's test was used to compare the findings on CBCT images and histological evaluation. Receiver operating characteristic (ROC) curves and logistic regression were used to evaluate the diagnostic accuracy of different cross-sections. The maximum AZ-value was achieved at 3-mm thickness/filtration 2. However, the differences between 1-mm thickness/filtration 2 and 1-mm thickness/filtration 1 were not significant (P=0.728 and 0.868, respectively). The minimum AZ-value was achieved at 5-mm thickness/filtration 0. Although CBCT is not sufficiently effective in detecting caries, the best cross-sections for detection of proximal caries were achieved at 3-mm thickness/filtration 2, 1-mm thickness/filtration 2 and 1-mm thickness/filtration 1.

  19. Effect of Filtration and Thickness of Cross-Sections of Cone Beam Computed Tomography Images on Detection of Proximal Caries

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    Mehrdad Abdinian

    2017-10-01

    Full Text Available Objectives: When a patient has cone beam computed tomography (CBCT images based on the treatment plan, it is possible to use these images for evaluation of caries, and there is no need for new radiographs, according to the "as low as reasonably achievable" (ALARA principle. The aim of this study was to determine the effect of filtration and thickness of CBCT cross-sections on detection of proximal caries.Materials and Methods: In this in-vitro study, 100 teeth were placed in the dental sockets of a dry skull, and were fixed in normal proximal contacts. CBCT images were taken and were evaluated by two observers on the panoramic view at 1-, 3- and 5-mm-thick cross-sections, with the use of filtrations 0, 1 and 2. Afterwards, the samples were sectioned and underwent a histological evaluation. McNemar’s test was used to compare the findings on CBCT images and histological evaluation. Receiver operating characteristic (ROC curves and logistic regression were used to evaluate the diagnostic accuracy of different cross-sections.Results: The maximum AZ-value was achieved at 3-mm thickness/filtration 2. However, the differences between 1-mm thickness/filtration 2 and 1-mm thickness/filtration 1 were not significant (P=0.728 and 0.868, respectively. The minimum AZ-value was achieved at 5-mm thickness/filtration 0.Conclusions: Although CBCT is not sufficiently effective in detecting caries, the best cross-sections for detection of proximal caries were achieved at 3-mm thickness/filtration 2, 1-mm thickness/filtration 2 and 1-mm thickness/filtration 1.

  20. Quantitative investigation of palatal bone depth and cortical bone thickness for mini-implant placement in adults.

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    Baumgaertel, Sebastian

    2009-07-01

    Cortical bone thickness and overall bone depth are important factors to consider when placing an orthodontic mini-implant. The purpose of this study was to investigate both variables in the palate quantitatively to aid clinicians in planning successful mini-implant placements. Thirty dry skulls were imaged with cone-beam computed tomography technology. Coronal slices were generated on which overall bone depth and cortical bone thickness were measured at 4 levels and 34 palatal placement sites. One-way analysis of variance (ANOVA) was used for data analysis. Overall bone depth decreased with increasing distance from the midsagittal plane and from the anterior to the posterior palatal regions. Cortical bone thickness decreased from anterior to posterior, but no differences were detectable within measurement levels. Bone depth and cortical bone thickness of the palate were most favorable for temporary anchorage device placement at the level of the first and second premolars. This information could aid clinicians in choosing suitable palatal placement sites for orthodontic mini-implants.

  1. A Preliminary Study of the Influence of Age of Onset and Childhood Trauma on Cortical Thickness in Major Depressive Disorder

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    Natalia Jaworska

    2014-01-01

    Full Text Available Background. Major depressive disorder (MDD neural underpinnings may differ based on onset age and childhood trauma. We assessed cortical thickness in patients who differed in age of MDD onset and examined trauma history influence. Methods. Adults with MDD (N=36 and controls (HC; N=18 underwent magnetic resonance imaging. Twenty patients had MDD onset 25 years of age (adult onset. The MDD group was also subdivided into those with (N=12 and without (N=19 physical and/or sexual abuse as assessed by the Childhood Trauma Questionnaire (CTQ. Cortical thickness was analyzed with FreeSurfer software. Results. Thicker frontal pole and a tendency for thinner transverse temporal cortices existed in MDD. The former was driven by the pediatric onset group and abuse history (independently, particularly in the right frontal pole. Inverse correlations existed between CTQ scores and frontal pole cortex thickness. A similar inverse relation existed with left inferior and right superior parietal cortex thickness. The superior temporal cortex tended to be thinner in pediatric versus adult onset groups with childhood abuse. Conclusions. This preliminary work suggests neural differences between pediatric and adult MDD onset. Trauma history also contributes to cytoarchitectural modulation. Thickened frontal pole cortices as a compensatory mechanism in MDD warrant evaluation.

  2. Relationship among Types of Growth Patterns, Buccolingual Molar Inclination and Cortical Bone Thickness of the Mandible: A CT Scan Study

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    Narendra Shriram Sharma

    2012-01-01

    Conclusion: The results of this study provide evidence that a significant, but complex relationship exists between structures of the mandibular body and types of growth pattern. The morphological features that relate to masticatory function and types of growth pattern are associated with the cortical bone thickness of the mandibular body and the buccolingual inclination of the first and second permanent mandibular molars.

  3. Cortical thickness in adolescent marijuana and alcohol users: A three-year prospective study from adolescence to young adulthood

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    Joanna Jacobus

    2015-12-01

    Full Text Available Studies suggest marijuana impacts gray and white matter neural tissue development, however few prospective studies have determined the relationship between cortical thickness and cannabis use spanning adolescence to young adulthood. This study aimed to understand how heavy marijuana use influences cortical thickness trajectories across adolescence. Subjects were adolescents with heavy marijuana use and concomitant alcohol use (MJ + ALC, n = 30 and controls (CON, n = 38 with limited substance use histories. Participants underwent magnetic resonance imaging and comprehensive substance use assessment at three independent time points. Repeated measures analysis of covariance was used to look at main effects of group, time, and Group × Time interactions on cortical thickness. MJ + ALC showed thicker cortical estimates across the brain (23 regions, particularly in frontal and parietal lobes (ps < .05. More cumulative marijuana use was associated with increased thickness estimates by 3-year follow-up (ps < .05. Heavy marijuana use during adolescence and into young adulthood may be associated with altered neural tissue development and interference with neuromaturation that can have neurobehavioral consequences. Continued follow-up of adolescent marijuana users will help understand ongoing neural changes that are associated with development of problematic use into adulthood, as well as potential for neural recovery with cessation of use.

  4. Increased cortical area and thickness in the distal radius in subjects with SHOX-gene mutation.

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    Frederiksen, A L; Hansen, S; Brixen, K; Frost, M

    2014-12-01

    Short-stature homeobox (SHOX) gene haploinsufficiency may cause skeletal dysplasia including Léri-Weill Dyschondrosteosis (LWD), a clinical entity characterised by the triad of low height, mesomelic disproportion and Madelung's deformity of the wrist. Bone microarchitecture and estimated strength in adult SHOX mutation carriers have not been examined. Twenty-two subjects with a SHOX mutation including 7 males and 15 females with a median age of 38.8 [21.1-52.2] years were recruited from five unrelated families. The control group consisted of 22 healthy subjects matched on age and sex. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. Bone geometry, volumetric density, microarchitecture and finite element estimated (FEA) bone strength were measured using high-resolution peripheral quantitative computed tomography (HR-pQCT). A full region of interest (ROI) image analysis and height-matched ROI analyses adjusting for differences in body height between the two groups were performed. Areal BMD and T-scores showed no significant differences between cases and controls. Total radius area was smaller in cases than controls (207 [176-263] vs. 273 [226-298] mm, pRadius cortical bone area (74 ± 20 vs. 58 ± 17 mm(2), p=0.01) and thickness (1.16 ± 0.30 vs. 0.84 ± 0.26 mm, pRadius trabecular bone area (119 [103-192] vs. 202 [168-247] mm(2), pradius and tibia cortical porosity or FEA failure load between groups. A segment of cortical bone defect was identified in the distal radius adjacent to ulna in five unrelated SHOX mutation carriers. Subjects with a SHOX mutation presented with a different bone geometry in radius and tibia while there were no differences in BMD or failure load compared to controls, suggesting that mutations in SHOX gene may have an impact on bone microarchitecture albeit not bone strength. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Is there a relation between novelty seeking, striatal dopamine release and frontal cortical thickness?

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    Natalia Jaworska

    Full Text Available Novelty-seeking (NS and impulsive personality traits have been proposed to reflect an interplay between fronto-cortical and limbic systems, including the limbic striatum (LS. Although neuroimaging studies have provided some evidence for this, most are comprised of small samples and many report surprisingly large effects given the challenges of trying to relate a snapshot of brain function or structure to an entity as complex as personality. The current work tested a priori hypotheses about associations between striatal dopamine (DA release, cortical thickness (CT, and NS in a large sample of healthy adults.Fifty-two healthy adults (45M/7F; age: 23.8±4.93 underwent two positron emission tomography scans with [11C]raclopride (specific for striatal DA D2/3 receptors with or without amphetamine (0.3 mg/kg, p.o.. Structural magnetic resonance image scans were acquired, as were Tridimensional Personality Questionnaire data. Amphetamine-induced changes in [11C]raclopride binding potential values (ΔBPND were examined in the limbic, sensorimotor (SMS and associative (AST striatum. CT measures, adjusted for whole brain volume, were extracted from the dorsolateral sensorimotor and ventromedial/limbic cortices.BPND values were lower in the amphetamine vs. no-drug sessions, with the largest effect in the LS. When comparing low vs. high LS ΔBPND groups (median split, higher NS2 (impulsiveness scores were found in the high ΔBPND group. Partial correlations (age and gender as covariates yielded a negative relation between ASTS ΔBPND and sensorimotor CT; trends for inverse associations existed between ΔBPND values in other striatal regions and frontal CT. In other words, the greater the amphetamine-induced striatal DA response, the thinner the frontal cortex.These data expand upon previously reported associations between striatal DA release in the LS and both NS related impulsiveness and CT in the largest sample reported to date. The findings add to the

  6. Maternal pre-pregnancy obesity and child ADHD symptoms, executive function and cortical thickness

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    Claudia Buss

    2012-09-01

    Full Text Available Rationale/statement of the problem : Increasing evidence suggests exposure to adverse conditions in intrauterine life may increase the risk of developing attention-deficit/hyperactivity disorder (ADHD in childhood. High maternal pre-pregnancy body mass index (BMI has been shown to predict child ADHD symptoms; however, the neurocognitive processes underlying this relationship are not known. The aim of the present study was to test the hypothesis that this association is mediated by alterations in child executive function and cortical development. Methods : A population-based cohort of 174 children (mean age = 7.3±0.9 (SD years, 55% girls was evaluated for ADHD symptoms, using the Child Behavior Checklist, and for neurocognitive function, using the Go/No-go Task. This cohort had been followed prospectively from early gestation and birth through infancy and childhood with serial measures of maternal and child prenatal and postnatal factors. In 108 children, a structural MRI scan was acquired and the association between maternal obesity and child cortical thickness was investigated using Freesurfer software. Results : Maternal pre-pregnancy BMI was a significant predictor of child ADHD symptoms (F (1,158=4.80, p = 0.03 and of child performance on the Go/No-go Task (F (1,157=8.37, p=0.004 after controlling for key potential confounding variables. A test of the mediation model revealed that the association between higher maternal pre-pregnancy BMI and child ADHD symptoms was mediated by impaired executive function (inefficient/less attentive processing; Sobel test: t=2.39 (±0.002, SEM; p=0.02. Interestingly, after controlling for key potential confounding variables pre-pregnancy obesity was furthermore associated with region-specific thinner cortices, including regions previously reported to be thinner in children with ADHD, like the prefrontal cortex. Conclusion : To the best of our knowledge, this is the first study to report the

  7. Laminar Thickness Alterations in the Fronto-Parietal Cortical Mantle of Patients with Attention-Deficit/Hyperactivity Disorder

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    Ramos-Quiroga, J. Antoni; Fernández, Vanesa Richarte; Picado, Marisol; Bosch, Rosa; Soliva, Juan Carlos; Rovira, Mariana; Vives, Yolanda; Bulbena, Antonio; Tobeña, Adolf; Casas, Miguel; Vilarroya, Oscar

    2012-01-01

    Although Attention-Deficit/Hyperactivity Disorder (ADHD) was initially regarded as a disorder exclusive to childhood, nowadays its prevalence in adulthood is well established. The development of novel techniques for quantifying the thickness of the cerebral mantle allows the further exploration of the neuroanatomical profiles underlying the child and adult form of the disorder. To examine the cortical mantle in children and adults with ADHD, we applied a vertex-wise analysis of cortical thickness to anatomical brain MRI scans acquired from children with (n = 43) and without ADHD (n = 41), as well as a group of adult neurotypical individuals (n = 31), adult patients with a history of stimulant treatment (n = 31) and medication-naïve adults with ADHD (n = 24). We observed several clusters of reduced laminar cortical thickness in ADHD patients in comparison to neurotypical individuals. These differences were primarily located in the dorsal attention network, including the bilateral inferior and superior parietal cortex and a section of the frontal cortex (centered on the superior frontal and precentral gyrus bilaterally). Further laminar thickness deficits were observed in the bilateral orbitofrontal cortex and medial occipital cortex. The deficits in the cortical surface were especially pronounced in the child sample, while adult patients showed a more typical laminar thickness across the cerebral mantle. These findings show that the neuroanatomical profile of ADHD, especially the childhood form of the disorder, involves robust alterations in the cortical mantle, which are most prominent in brain regions subserving attentional processing. PMID:23239964

  8. Laminar thickness alterations in the fronto-parietal cortical mantle of patients with attention-deficit/hyperactivity disorder.

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    Elseline Hoekzema

    Full Text Available Although Attention-Deficit/Hyperactivity Disorder (ADHD was initially regarded as a disorder exclusive to childhood, nowadays its prevalence in adulthood is well established. The development of novel techniques for quantifying the thickness of the cerebral mantle allows the further exploration of the neuroanatomical profiles underlying the child and adult form of the disorder. To examine the cortical mantle in children and adults with ADHD, we applied a vertex-wise analysis of cortical thickness to anatomical brain MRI scans acquired from children with (n = 43 and without ADHD (n = 41, as well as a group of adult neurotypical individuals (n = 31, adult patients with a history of stimulant treatment (n = 31 and medication-naïve adults with ADHD (n = 24. We observed several clusters of reduced laminar cortical thickness in ADHD patients in comparison to neurotypical individuals. These differences were primarily located in the dorsal attention network, including the bilateral inferior and superior parietal cortex and a section of the frontal cortex (centered on the superior frontal and precentral gyrus bilaterally. Further laminar thickness deficits were observed in the bilateral orbitofrontal cortex and medial occipital cortex. The deficits in the cortical surface were especially pronounced in the child sample, while adult patients showed a more typical laminar thickness across the cerebral mantle. These findings show that the neuroanatomical profile of ADHD, especially the childhood form of the disorder, involves robust alterations in the cortical mantle, which are most prominent in brain regions subserving attentional processing.

  9. Anxious/depressed symptoms are linked to right ventromedial prefrontal cortical thickness maturation in healthy children and young adults.

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    Ducharme, Simon; Albaugh, Matthew D; Hudziak, James J; Botteron, Kelly N; Nguyen, Tuong-Vi; Truong, Catherine; Evans, Alan C; Karama, Sherif

    2014-11-01

    The relationship between anxious/depressed traits and neuromaturation remains largely unstudied. Characterizing this relationship during healthy neurodevelopment is critical to understanding processes associated with the emergence of child/adolescent onset mood/anxiety disorders. In this study, mixed-effects models were used to determine longitudinal cortical thickness correlates of Child Behavior Checklist (CBCL) and Young Adult Self Report Anxious/Depressed scores in healthy children. Analyses included 341 subjects from 4.9 to 22.3 year-old with repeated MRI at up to 3 time points, at 2-year intervals (586 MRI scans). There was a significant "CBCL Anxious/Depressed by Age" interaction on cortical thickness in the right ventromedial prefrontal cortex (vmPFC), including the medial orbito-frontal, gyrus rectus, and subgenual anterior cingulate areas. Anxious/Depressed scores were negatively associated with thickness at younger ages (rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. Reduced Regional Cortical Thickness Rate of Change in Donepezil-Treated Subjects With Suspected Prodromal Alzheimer's Disease.

    Science.gov (United States)

    Cavedo, Enrica; Dubois, Bruno; Colliot, Olivier; Lista, Simone; Croisile, Bernard; Tisserand, Guy Louis; Touchon, Jacques; Bonafe, Alain; Ousset, Pierre J; Rouaud, Olivier; Ricolfi, Fréderic; Vighetto, Alain; Pasquier, Florence; Galluzzi, Samantha; Delmaire, Christine; Ceccaldi, Mathieu; Girard, Nadine; Lehericy, Stéphane; Duveau, Françoise; Chupin, Marie; Sarazin, Marie; Dormont, Didier; Hampel, Harald

    2016-12-01

    Cortical thinning, previously identified during prodromal stages of Alzheimer's disease (AD), is a "candidate" biomarker implemented in AD clinical therapy trials. We investigated the effect of donepezil treatment on cortical thickness in mild cognitively impaired subjects with the amnestic syndrome of the hippocampal type, a prodromal at-risk group for progression to AD dementia. Data were from a longitudinal analysis of a community-based multicenter suspected prodromal AD cohort diagnosed by the Free and Cued Selective Reminding Test (81 donepezil vs 92 placebo) enrolled in a double-blind, randomized, placebo-controlled parallel group design using donepezil (10 mg/day). The study started in November 2006 and concluded in August 2010. All subjects underwent 2 brain structural magnetic resonance imaging (MRI) scans, at baseline and at the end of the trial. Structural MRI images had been processed using the automated pipeline for longitudinal segmentation and surface reconstruction implemented in FreeSurfer. The primary outcome measure of this post hoc study was the annualized percentage change (APC) of cortical thickness. The donepezil group exhibited reduced APC cortical thinning compared to placebo in the rostral anterior cingulate (right: P = .048; left: P = .032), the orbitofrontal (right: P = .012; left: P donepezil treatment may have an impact on cortical structure/morphology in areas innervated by the medial and lateral cholinergic pathways. ClinicalTrials.gov identifier: NCT00403520.

  11. Greater Cortical Thickness in Elderly Female Yoga Practitioners—A Cross-Sectional Study

    Directory of Open Access Journals (Sweden)

    Rui F. Afonso

    2017-06-01

    Full Text Available Yoga, a mind-body activity that requires attentional engagement, has been associated with positive changes in brain structure and function, especially in areas related to awareness, attention, executive functions and memory. Normal aging, on the other hand, has also been associated with structural and functional brain changes, but these generally involve decreased cognitive functions. The aim of this cross-sectional study was to compare brain cortical thickness (CT in elderly yoga practitioners and a group of age-matched healthy non-practitioners. We tested 21 older women who had practiced hatha yoga for at least 8 years and 21 women naive to yoga, meditation or any mind-body interventions who were matched to the first group in age, years of formal education and physical activity level. A T1-weighted MPRAGE sequence was acquired for each participant. Yoga practitioners showed significantly greater CT in a left prefrontal lobe cluster, which included portions of the lateral middle frontal gyrus, anterior superior frontal gyrus and dorsal superior frontal gyrus. We found greater CT in the left prefrontal cortex of healthy elderly women who trained yoga for a minimum of 8 years compared with women in the control group.

  12. Multiple bases of human intelligence revealed by cortical thickness and neural activation.

    Science.gov (United States)

    Choi, Yu Yong; Shamosh, Noah A; Cho, Sun Hee; DeYoung, Colin G; Lee, Min Joo; Lee, Jong-Min; Kim, Sun I; Cho, Zang-Hee; Kim, Kyungjin; Gray, Jeremy R; Lee, Kun Ho

    2008-10-08

    We hypothesized that individual differences in intelligence (Spearman's g) are supported by multiple brain regions, and in particular that fluid (gF) and crystallized (gC) components of intelligence are related to brain function and structure with a distinct profile of association across brain regions. In 225 healthy young adults scanned with structural and functional magnetic resonance imaging sequences, regions of interest (ROIs) were defined on the basis of a correlation between g and either brain structure or brain function. In these ROIs, gC was more strongly related to structure (cortical thickness) than function, whereas gF was more strongly related to function (blood oxygenation level-dependent signal during reasoning) than structure. We further validated this finding by generating a neurometric prediction model of intelligence quotient (IQ) that explained 50% of variance in IQ in an independent sample. The data compel a nuanced view of the neurobiology of intelligence, providing the most persuasive evidence to date for theories emphasizing multiple distributed brain regions differing in function.

  13. A computerized tomographic study on the location of the mandibular canal and the cortical thickness of the mandible

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Ssang Yong; Song, Nam Kyu; Koh, Kwang Joon [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Chonbuk National University, Chonju (Korea, Republic of)

    1997-02-15

    The location of the mandibular canal and the cortical thickness of the mandible is important in the practice of dentistry. This study was preformed on twenty chosen dry mandibles, which were of adults and included fully erupted premolars and molars. The purpose of this study was to evaluate the location of the mandibular canal and the cortical thickness of the mandible on computed tomograms and to aid in the surgical treatment plans. The obtained results were as follows : 1. The horizontal distance between the mandibular canal and the buccal external border was 6.6 {+-} 0.9 mm on So (mesial root of the first molar), and it was increased posteriorly. The horizontal distance between the mandibular canal and the lingual external border was 4.1 {+-} 1.1 mm on So, and it was decreased posteriorly. 2. The vertical distance between the alveolar crest and the mandibular canal was 16.9 {+-} 1.6 mm on So, and it w as decreased posteriorly. The vertical distance between the inferior border of mandible and mandibular canal was 8.8 {+-} 1. 3 mm on So. and it was increased anteriorly and posteriorly. 3. The thickness of the buccal cortical plate was 2.2 {+-} 0.4 mm on So. and it was increased posteriorly. But, t hat of the lingual cortical plate was 2.0 {+-} 0.6 mm on So. and it was decreased posteriorly. 4. The area of the buccal cortical plate was 66.5 {+-} 1.0 mm{sup 2} on So. and it was increased posteriorly . But, that of the lingual cortical plate was 65.8 {+-} 0.9 mm{sup 2} on So and it was decreased posteriorly.

  14. Cortical thickness in adolescent marijuana and alcohol users: A three-year prospective study from adolescence to young adulthood.

    Science.gov (United States)

    Jacobus, Joanna; Squeglia, Lindsay M; Meruelo, Alejandro D; Castro, Norma; Brumback, Ty; Giedd, Jay N; Tapert, Susan F

    2015-12-01

    Studies suggest marijuana impacts gray and white matter neural tissue development, however few prospective studies have determined the relationship between cortical thickness and cannabis use spanning adolescence to young adulthood. This study aimed to understand how heavy marijuana use influences cortical thickness trajectories across adolescence. Subjects were adolescents with heavy marijuana use and concomitant alcohol use (MJ+ALC, n=30) and controls (CON, n=38) with limited substance use histories. Participants underwent magnetic resonance imaging and comprehensive substance use assessment at three independent time points. Repeated measures analysis of covariance was used to look at main effects of group, time, and Group × Time interactions on cortical thickness. MJ+ALC showed thicker cortical estimates across the brain (23 regions), particularly in frontal and parietal lobes (psadolescence and into young adulthood may be associated with altered neural tissue development and interference with neuromaturation that can have neurobehavioral consequences. Continued follow-up of adolescent marijuana users will help understand ongoing neural changes that are associated with development of problematic use into adulthood, as well as potential for neural recovery with cessation of use. Published by Elsevier Ltd.

  15. Surface-based morphometry of the cortical architecture of autism spectrum disorders: volume, thickness, area, and gyrification.

    Science.gov (United States)

    Libero, Lauren E; DeRamus, Thomas P; Deshpande, Hrishikesh D; Kana, Rajesh K

    2014-09-01

    Structural neuroimaging studies of autism spectrum disorder (ASD) have uncovered widespread neuroanatomical abnormalities, which may have a significant impact on brain function, connectivity, and on behavioral symptoms of autism. The findings of previous structural MRI studies have largely been distributed across several brain areas, with limited consistency. The current study examined neuroanatomical abnormalities by comparing surface-based measures of cortical morphology (CT: cortical thickness, CSA: cortical surface area, CV: cortical volume, and GI: gyrification index) in 55 high-functioning children and adults with ASD to 60 age-and-IQ-matched typically developing (TD) peers. A few brain areas, the fusiform gyrus (FG), middle temporal gyrus (MTG), and inferior frontal gyrus (IFG), emerged to be primarily different in their morphology between the two groups. Compared to TD participants, ASD participants had significantly smaller CV in left MTG, reduced CSA in bilateral MTG and FG, reduced GI in left supramarginal gyrus, and significantly increased CT in the pars opercularis of the IFG. As a function of age, ASD participants had significant reductions in: CT in the pars opercularis, CSA of the left rostral middle frontal gyrus, and GI for left supramarginal gyrus. Thus, alterations in cortical morphology in ASD were seen primarily in regions that are considered part of the social brain. Overall, these findings point to: neuroanatomical alterations in social brain areas, developmental differences in neuroanatomy, and the need to study neuroanatomy at multiple levels in order to better characterize the cortical architecture of ASD. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Relationships Between Altered Functional Magnetic Resonance Imaging Activation and Cortical Thickness in Patients With Euthymic Bipolar I Disorder.

    Science.gov (United States)

    Joshi, Shantanu H; Vizueta, Nathalie; Foland-Ross, Lara; Townsend, Jennifer D; Bookheimer, Susan Y; Thompson, Paul M; Narr, Katherine L; Altshuler, Lori L

    2016-11-01

    Performance during cognitive control functional magnetic resonance imaging (fMRI) tasks are associated with frontal lobe hypoactivation in patients with bipolar disorder, even while euthymic. Here, we study the structural underpinnings for this functional abnormality simultaneously with brain activation data. In a sample of ninety adults (45 with inter-episode Bipolar I disorder and 45 healthy controls), we explored whether abnormal functional activation patterns in bipolar euthymic subjects during a Go-NoGo fMRI task are associated with regional deficits in cortical gray matter thickness in the same regions. Cross-sectional differences in fMRI activation were used to form a-priori hypotheses for region-of-interest cortical gray matter thickness analyses. fMRI BOLD to structural magnetic resonance imaging (sMRI) thickness correlations were conducted across the sample and within patients and controls separately. During response inhibition (NoGo minus Go), bipolar subjects showed significant hypoactivation and reduced thickness in the inferior frontal cortex (IFC), superior frontal gyrus and cingulate compared to controls. Cingulate hypoactivation corresponded with reduced regional thickness. A significant activation by disease state interaction was observed with thickness in left prefrontal areas. Reduced cingulate fMRI activation is associated with reduced cortical thickness. In the left frontal lobe, a thinner cortex was associated with increased fMRI activation in patients, but showed a reverse trend in controls. These findings suggest that reduced activation in the IFC and cingulate during a response inhibition task may have an underlying structural etiology, which may explain task-related functional hypoactivation that persists even when patients are euthymic.

  17. Brain morphology and cortical thickness variations in systemic lupus erythematosus patients: Differences among neurological, psychiatric, and nonneuropsychiatric manifestations.

    Science.gov (United States)

    Zimmermann, Nicolle; Goulart Corrêa, Diogo; Tukamoto, Gustavo; Netto, Tania; Batista Pereira, Denis; Paz Fonseca, Rochele; Gasparetto, Emerson Leandro

    2017-07-01

    To determine whether systemic lupus erythematosus (SLE) affecting subcortical white matter volumes, deep gray matter volumes, and cortical thickness differ between groups of SLE patients with psychiatric (P-SLE), neurological (N-SLE), or nonneuropsychiatric (non-NPSLE) presentations. Sixty-seven participants were divided into three groups (P-SLE [n = 19], N-SLE [n = 12], and non-NPSLE [n = 36]) and examined with a 1.5T MRI scanner. The images were segmented in FreeSurfer software into volumetric and cortical thickness measures using T1 3D magnetization prepared rapid gradient echo-weighted imaging. For comparative analyses of volume, multivariate analyses of covariance (MANCOVA) were applied followed by Bonferroni post-hoc tests, with age as a covariate. For cortical thickness analyses, the groups were compared with the Query Design Estimate Contrast tool adjusted for age. Globus pallidus volumes in both left (P ≤ 0.01) and right (P ≤ 0.05) hemispheres were larger in the N-SLE group than in the non-NPSLE group, and the left GP volume was greater in the N-SLE group than in the P-SLE group (P ≤ 0.05) (MANCOVA, post-hoc Bonferroni). The P-SLE group presented with thinning of cortical areas relative to the N-SLE (predominantly in the left parietal and right frontal and parietal regions) (P ≤ 0.05) and non-NPSLE (predominantly in parietal and occipital regions) (P ≤ 0.05) groups, whereas the N-SLE group presented with thickening of cortical areas (mostly right frontal and left parietal regions) relative to the non-NPSLE (P ≤ 0.05) and P-SLE groups. N-SLE patients had greater local volumes and cortical thicknesses than the other two groups, whereas P-SLE patients presented with decreased volumes and cortical thinning. These findings provide evidence of distinct neuroanatomical abnormalities in neurological versus psychiatric manifestations of SLE. 2 Technical Efficacy: Stage 3 J. MAGN. RESON. IMAGING 2017;46:150-158. © 2016 International Society

  18. The contribution of the left mid-fusiform cortical thickness to Chinese and English reading in a large Chinese sample.

    Science.gov (United States)

    Zhang, Mingxia; Li, Jin; Chen, Chuansheng; Mei, Leilei; Xue, Gui; Lu, Zhonglin; Chen, Chunhui; He, Qinghua; Wei, Miao; Dong, Qi

    2013-01-15

    Previous functional neuroimaging studies have shown that the left mid-fusiform cortex plays a critical role in reading. However, there is very limited research relating this region's anatomical structure to reading performance either in native or second language. Using structural MRI and three reading tasks (Chinese characters, English words, and alphabetic pseudowords) and a non-reading task (visual-auditory learning), this study investigated the contributions of the left mid-fusiform cortical thickness to reading in a large sample of 226 Chinese subjects. Results showed that the cortical thickness in the left mid-fusiform gyrus was positively correlated with performance on all three reading tasks but not with the performance on the non-reading task. Our findings provide structural evidence for the left mid-fusiform cortex as the "gateway" region for reading Chinese and English. The absence of the association between the left mid-fusiform cortical thickness and non-reading performance implied the specific role of this area in reading skills, not in general language skills. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. The Right Hemisphere Planum Temporale Supports Enhanced Visual Motion Detection Ability in Deaf People: Evidence from Cortical Thickness

    Directory of Open Access Journals (Sweden)

    Martha M. Shiell

    2016-01-01

    Full Text Available After sensory loss, the deprived cortex can reorganize to process information from the remaining modalities, a phenomenon known as cross-modal reorganization. In blind people this cross-modal processing supports compensatory behavioural enhancements in the nondeprived modalities. Deaf people also show some compensatory visual enhancements, but a direct relationship between these abilities and cross-modally reorganized auditory cortex has only been established in an animal model, the congenitally deaf cat, and not in humans. Using T1-weighted magnetic resonance imaging, we measured cortical thickness in the planum temporale, Heschl’s gyrus and sulcus, the middle temporal area MT+, and the calcarine sulcus, in early-deaf persons. We tested for a correlation between this measure and visual motion detection thresholds, a visual function where deaf people show enhancements as compared to hearing. We found that the cortical thickness of a region in the right hemisphere planum temporale, typically an auditory region, was greater in deaf individuals with better visual motion detection thresholds. This same region has previously been implicated in functional imaging studies as important for functional reorganization. The structure-behaviour correlation observed here demonstrates this area’s involvement in compensatory vision and indicates an anatomical correlate, increased cortical thickness, of cross-modal plasticity.

  20. Right anterior cingulate cortical thickness and bilateral striatal volume correlate with child behavior checklist aggressive behavior scores in healthy children.

    Science.gov (United States)

    Ducharme, Simon; Hudziak, James J; Botteron, Kelly N; Ganjavi, Hooman; Lepage, Claude; Collins, D Louis; Albaugh, Matthew D; Evans, Alan C; Karama, Sherif

    2011-08-01

    The anterior cingulate cortex (ACC), orbitofrontal cortex (OFC), and basal ganglia have been implicated in pathological aggression. This study aimed at identifying neuroanatomical correlates of impulsive aggression in healthy children. Data from 193 representative 6- to 18-year-old healthy children were obtained from the National Institutes of Health Magnetic Resonance Imaging Study of Normal Brain Development after a blinded quality control. Cortical thickness and subcortical volumes were obtained with automated software. Aggression levels were measured with the Aggressive Behavior scale (AGG) of the Child Behavior Checklist. AGG scores were regressed against cortical thickness and basal ganglia volumes using first- and second-order linear models while controlling for age, gender, scanner site, and total brain volume. Gender by AGG interactions were analyzed. There were positive associations between bilateral striatal volumes and AGG scores (right: r = .238, p = .001; left: r = .188, p = .01). A significant association was found with right ACC and subgenual ACC cortical thickness in a second-order linear model (p right ACC cortex. An AGG by gender interaction trend was found in bilateral OFC and ACC associations with AGG scores. This study shows the existence of relationships between impulsive aggression in healthy children and the structure of the striatum and right ACC. It also suggests the existence of gender-specific patterns of association in OFC/ACC gray matter. These results may guide research on oppositional-defiant and conduct disorders. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  1. Biomechanical effect of medial cortical support and medial screw support on locking plate fixation in proximal humeral fractures with a medial gap: a finite element analysis.

    Science.gov (United States)

    Yang, Pan; Zhang, Ying; Liu, Jian; Xiao, Jin; Ma, Li Min; Zhu, Chang Rong

    2015-01-01

    This finite element analysis aimed to examine the effect of medial cortical support and medial screw support on loads at the implant-bone interface of locking plate fixation of proximal humeral fractures with a medial gap. An intact humerus from a healthy volunteer was used as the basis for a 3-dimensional (3D) computer-aided design (CAD) model. The 3D CAD model of the locking plate system was based on information in the manufacturer's catalogue. The proximal part of the humerus was osteotomized to create standard three-part fractures, which were then divided into a -MSC group (which lacked medial cortical support, and in which fractures with a 5-mm medial bone gap simulated this lack) and +MCS group (which had medial cortical support, and in which fractures with medial cortical-to-cortical contact simulated this). Both fracture groups were respectively fixed with either +MSS (in which medial screw support was simulated by the addition of two calcar screws to the locking plate system), or with -MSS (in which the lack of medial screw support was simulated by absence of the two additional calcar screws to the locking plate system). All the modeling was conducted to represent 90° arm abduction. On the screw-bone interface, medial screw support and medial cortical support decreased maximum shear stress by 17% and 23% respectively. On the locking plate, medial screw support and medial cortical support decreased maximum von Mises stress by 11% and 22% respectively. However, a combination of these two appeared to decrease maximum shear stress by 56% for the screw-bone interface, and maximum von Mises stress by 54% for the locking plate. Placement of calcar screws combined with good medial cortical contact in varus in locking plate fixation of proximal humeral fractures with a medial gap may provide optimal stability for the fixation.

  2. Mild traumatic brain injury is associated with reduced cortical thickness in those at risk for Alzheimer's disease.

    Science.gov (United States)

    Hayes, Jasmeet P; Logue, Mark W; Sadeh, Naomi; Spielberg, Jeffrey M; Verfaellie, Mieke; Hayes, Scott M; Reagan, Andrew; Salat, David H; Wolf, Erika J; McGlinchey, Regina E; Milberg, William P; Stone, Annjanette; Schichman, Steven A; Miller, Mark W

    2017-03-01

    Moderate-to-severe traumatic brain injury is one of the strongest environmental risk factors for the development of neurodegenerative diseases such as late-onset Alzheimer's disease, although it is unclear whether mild traumatic brain injury, or concussion, also confers risk. This study examined mild traumatic brain injury and genetic risk as predictors of reduced cortical thickness in brain regions previously associated with early Alzheimer's disease, and their relationship with episodic memory. Participants were 160 Iraq and Afghanistan War veterans between the ages of 19 and 58, many of whom carried mild traumatic brain injury and post-traumatic stress disorder diagnoses. Whole-genome polygenic risk scores for the development of Alzheimer's disease were calculated using summary statistics from the largest Alzheimer's disease genome-wide association study to date. Results showed that mild traumatic brain injury moderated the relationship between genetic risk for Alzheimer's disease and cortical thickness, such that individuals with mild traumatic brain injury and high genetic risk showed reduced cortical thickness in Alzheimer's disease-vulnerable regions. Among males with mild traumatic brain injury, high genetic risk for Alzheimer's disease was associated with cortical thinning as a function of time since injury. A moderated mediation analysis showed that mild traumatic brain injury and high genetic risk indirectly influenced episodic memory performance through cortical thickness, suggesting that cortical thinning in Alzheimer's disease-vulnerable brain regions is a mechanism for reduced memory performance. Finally, analyses that examined the apolipoprotein E4 allele, post-traumatic stress disorder, and genetic risk for schizophrenia and depression confirmed the specificity of the Alzheimer's disease polygenic risk finding. These results provide evidence that mild traumatic brain injury is associated with greater neurodegeneration and reduced memory performance

  3. Relationship between neurotoxic kynurenine metabolites and reductions in right medial prefrontal cortical thickness in major depressive disorder.

    Science.gov (United States)

    Meier, Timothy B; Drevets, Wayne C; Wurfel, Brent E; Ford, Bart N; Morris, Harvey M; Victor, Teresa A; Bodurka, Jerzy; Teague, T Kent; Dantzer, Robert; Savitz, Jonathan

    2016-03-01

    Reductions in gray matter volume of the medial prefrontal cortex (mPFC), especially the rostral and subgenual anterior cingulate cortex (rACC, sgACC) are a widely reported finding in major depressive disorder (MDD). Inflammatory mediators, which are elevated in a subgroup of patients with MDD, activate the kynurenine metabolic pathway and increase production of neuroactive metabolites such as kynurenic acid (KynA), 3-hydroxykynurenine (3HK) and quinolinic acid (QA) which influence neuroplasticity. It is not known whether the alterations in brain structure and function observed in major depressive disorders are due to the direct effect of inflammatory mediators or the effects of neurotoxic kynurenine metabolites. Here, using partial posterior predictive distribution mediation analysis, we tested whether the serum concentrations of kynurenine pathway metabolites mediated reductions in cortical thickness in mPFC regions in MDD. Further, we tested whether any association between C-reactive protein (CRP) and cortical thickness would be mediated by kynurenine pathway metabolites. Seventy-three unmedicated subjects who met DSM-IV-TR criteria for MDD and 91 healthy controls (HC) completed MRI scanning using a pulse sequence optimized for tissue contrast resolution. Automated cortical parcellation was performed using the PALS-B12 Brodmann area atlas as implemented in FreeSurfer in order to compare the cortical thickness and cortical area of six PFC regions: Brodmann areas (BA) 9, 10, 11, 24, 25, and 32. Serum concentrations of kynurenine pathway metabolites were determined by high performance liquid chromatography (HPLC) with tandem mass spectrometry (MS/MS) detection, while high-sensitivity CRP concentration was measured immunoturbidimetrically. Compared with HCs, the MDD group showed a reduction in cortical thickness of the right BA24 (p<0.01) and BA32 (p<0.05) regions and MDD patients with a greater number of depressive episodes displayed thinner cortex in BA32 (p<0

  4. A surface based approach for cortical thickness comparison between PiB+ and PiB- healthy control subjects

    Science.gov (United States)

    Doré, Vincent; Bourgeat, Pierrick; Fripp, Jurgen; Acosta, Oscar; Chetelat, Gael; Szoeke, Cassandra; Ellis, Kathryn A.; Martins, Ralph N.; Villemagne, Victor; Masters, Colin L.; Ames, David; Rowe, Christopher C.; Salvado, Olivier

    2012-02-01

    β-amyloid has been shown to play a crucial role in Alzheimer's disease (AD). In vivo β-amyloid imaging using [11C]Pittsburgh compound Β (PiB) positron emission tomography has made it possible to analyze the relationship between β-amyloid deposition and different pathological markers involved in AD. PiB allows us to stratify the population between subjects which are likely to have prodromal AD, and those who don't. The comparison of the cortical thickness in these different groups is important to better understanding and detect the first symptoms of the disease which may lead to an earlier therapeutic care to reduce neurone loss. Several techniques have been developed to compare the cortical volume and/or thickness between AD and HC groups. However due to the noise introduced by the cortical thickness estimation and by the registration, these methods do not allow to unveil any major different when comparing prodromal AD groups with healthy control subjects group. To improve our understanding of where initial Alzheimer neurodegeneration occurs in the cortex we have developed a surface based technique, and have applied it to the discrimination between PIB-positive and PiB-negative HCs. We first identify the regions where AD patients show high cortical atrophy by using an AD/PiB- HC vertex-wise T-test. In each of these discriminating regions, comparison between PiB+ HC, PiB- HC and AD are performed. We found some significant differences between the two HC groups in the hippocampus and in the temporal lobe for both hemisphere and in the precuneus and occipital regions only for the left hemisphere.

  5. Longitudinal MRI study of cortical thickness, perfusion, and metabolite levels in major depressive disorder

    DEFF Research Database (Denmark)

    Järnum, Hanna; Eskildsen, Simon Fristed; Steffensen, Elena G.

    2011-01-01

    disorder (MDD) display morphologic, functional, and metabolic brain abnormalities in limbic-cortical regions at a baseline magnetic resonance (MR) scan and whether these changes are normalized in MDD patients in remission at a follow-up scan. Method:  A longitudinal 3.0-Tesla (T) magnetic resonance imaging...... with healthy controls at baseline. Conclusion:  Using novel MRI techniques, we have found abnormalities in cerebral regions related to cortical-limbic pathways in MDD patients....

  6. Individual-specific multi-scale finite element simulation of cortical bone of human proximal femur

    Science.gov (United States)

    Ascenzi, Maria-Grazia; Kawas, Neal P.; Lutz, Andre; Kardas, Dieter; Nackenhorst, Udo; Keyak, Joyce H.

    2013-07-01

    We present an innovative method to perform multi-scale finite element analyses of the cortical component of the femur using the individual's (1) computed tomography scan; and (2) a bone specimen obtained in conjunction with orthopedic surgery. The method enables study of micro-structural characteristics regulating strains and stresses under physiological loading conditions. The analysis of the micro-structural scenarios that cause variation of strain and stress is the first step in understanding the elevated strains and stresses in bone tissue, which are indicative of higher likelihood of micro-crack formation in bone, implicated in consequent remodeling or macroscopic bone fracture. Evidence that micro-structure varies with clinical history and contributes in significant, but poorly understood, ways to bone function, motivates the method's development, as does need for software tools to investigate relationships between macroscopic loading and micro-structure. Three applications - varying region of interest, bone mineral density, and orientation of collagen type I, illustrate the method. We show, in comparison between physiological loading and simple compression of a patient's femur, that strains computed at the multi-scale model's micro-level: (i) differ; and (ii) depend on local collagen-apatite orientation and degree of calcification. Our findings confirm the strain concentration role of osteocyte lacunae, important for mechano-transduction. We hypothesize occurrence of micro-crack formation, leading either to remodeling or macroscopic fracture, when the computed strains exceed the elastic range observed in micro-structural testing.

  7. Estimation of Remnant Dentin Thickness under Proximal Caries Using Digital Bitewing Radiography: An In-Vitro Study

    Directory of Open Access Journals (Sweden)

    Masoomeh Afsa

    2016-03-01

    Full Text Available Objectives: In restorative dentistry, it is essential to estimate the amount of remnant tooth structure after caries removal to make the best treatment plan. The present study was aimed to determine whether there is a correlation between the real thickness of remnant dentin under carious lesion and the radiographical measurement from photostimulable phosphor plates (PSPs. Methods: a whole number of 68 unrestored permanent human molar and premolar teeth with 82 proximal carious surfaces were mounted in an artificial arch. Digital bitewing radiographs with PSPs were taken, carious lesions were removed and radiographic imaging was repeated. Teeth were sectioned mesiodistally in two parts and thickness of remnant tooth structure to pulp was measured. Measurements of remnant dentin under caries from radiographic images and teeth structures were compared. Result: The mean measurements of remnant dentin on primary radiographs were statistically different from the measurements on teeth structures. The mean thickness of remnant dentin on tooth structure was around 30% less than what measured on radiographic image. Conclusion: The real thickness of remnant dentin under caries is about 70% of its thickness measured on digital bitewing radiographs prepared by PSPs as image receptor.

  8. Estimation of Remnant Dentin Thickness under Proximal Caries Using Digital Bitewing Radiography: An In-Vitro Study

    Directory of Open Access Journals (Sweden)

    Masoomeh Afsa

    2015-12-01

    Full Text Available Objectives: In restorative dentistry, it is essential to estimate the amount of remnant tooth structure after caries removal to make the best treatment plan. The present study was aimed to determine whether there is a correlation between the real thickness of remnant dentin under carious lesion and the radiographical measurement from photostimulable phosphor plates (PSPs. Methods: a whole number of 68 unrestored permanent human molar and premolar teeth with 82 proximal carious surfaces were mounted in an artificial arch. Digital bitewing radiographs with PSPs were taken, carious lesions were removed and radiographic imaging was repeated. Teeth were sectioned mesiodistally in two parts and thickness of remnant tooth structure to pulp was measured. Measurements of remnant dentin under caries from radiographic images and teeth structures were compared. Result: The mean measurements of remnant dentin on primary radiographs were statistically different from the measurements on teeth structures. The mean thickness of remnant dentin on tooth structure was around 30% less than what measured on radiographic image. Conclusion: The real thickness of remnant dentin under caries is about 70% of its thickness measured on digital bitewing radiographs prepared by PSPs as image receptor.

  9. Individual-specific multi-scale finite element simulation of cortical bone of human proximal femur

    Energy Technology Data Exchange (ETDEWEB)

    Ascenzi, Maria-Grazia, E-mail: mgascenzi@mednet.ucla.edu [UCLA/Orthopaedic Hospital, Department of Orthopaedic Surgery, Rehabilitation Bldg, Room 22-69, 1000 Veteran Avenue, University of California, Los Angeles, CA 90095 (United States); Kawas, Neal P., E-mail: nealkawas@ucla.edu [UCLA/Orthopaedic Hospital, Department of Orthopaedic Surgery, Rehabilitation Bldg, Room 22-69, 1000 Veteran Avenue, University of California, Los Angeles, CA 90095 (United States); Lutz, Andre, E-mail: andre.lutz@hotmail.de [Institute of Biomechanics and Numerical Mechanics, Leibniz University Hannover, 30167 Hannover (Germany); Kardas, Dieter, E-mail: kardas@ibnm.uni-hannover.de [ContiTech Vibration Control, Jaedekamp 30 None, 30419 Hannover (Germany); Nackenhorst, Udo, E-mail: nackenhorst@ibnm.uni-hannover.de [Institute of Biomechanics and Numerical Mechanics, Leibniz University Hannover, 30167 Hannover (Germany); Keyak, Joyce H., E-mail: jhkeyak@uci.edu [Department of Radiological Sciences, Medical Sciences I, Bldg 811, Room B140, University of California, Irvine, CA 92697-5000 (United States)

    2013-07-01

    We present an innovative method to perform multi-scale finite element analyses of the cortical component of the femur using the individual’s (1) computed tomography scan; and (2) a bone specimen obtained in conjunction with orthopedic surgery. The method enables study of micro-structural characteristics regulating strains and stresses under physiological loading conditions. The analysis of the micro-structural scenarios that cause variation of strain and stress is the first step in understanding the elevated strains and stresses in bone tissue, which are indicative of higher likelihood of micro-crack formation in bone, implicated in consequent remodeling or macroscopic bone fracture. Evidence that micro-structure varies with clinical history and contributes in significant, but poorly understood, ways to bone function, motivates the method’s development, as does need for software tools to investigate relationships between macroscopic loading and micro-structure. Three applications – varying region of interest, bone mineral density, and orientation of collagen type I, illustrate the method. We show, in comparison between physiological loading and simple compression of a patient’s femur, that strains computed at the multi-scale model’s micro-level: (i) differ; and (ii) depend on local collagen-apatite orientation and degree of calcification. Our findings confirm the strain concentration role of osteocyte lacunae, important for mechano-transduction. We hypothesize occurrence of micro-crack formation, leading either to remodeling or macroscopic fracture, when the computed strains exceed the elastic range observed in micro-structural testing.

  10. Retinal thickness correlates with parietal cortical atrophy in early-onset Alzheimer's disease and controls

    NARCIS (Netherlands)

    den Haan, Jurre; Janssen, Sarah F.; van de Kreeke, Jacoba A.; Scheltens, Philip; Verbraak, Frank D.; Bouwman, Femke H.

    2018-01-01

    The retina may reflect Alzheimer's disease (AD) neuropathological changes and is easily visualized with optical coherence tomography (OCT). Retinal thickness decrease has been correlated to AD, however, without information on amyloid status. We correlated retinal (layer) thickness to AD biomarkers

  11. Description of mandibular bone quality based on measurements of cortical thickness using Mental Index of male and female patients between 40-60 years old

    Energy Technology Data Exchange (ETDEWEB)

    Hardanti, Sylviana; Oscandar, Azhari; Oscandar, Fahmi [Faculty of Dentistry, Padjadjaran University, Bandung (Indonesia)

    2011-12-15

    The purpose of this study was to obtain the description of the mandibular bone quality of male and female patients between 40-60 years old and their differences based on mandibular cortical bone thickness measured using Mental Index (MI). Forty digital panoramic radiographs, which consisted of twenty male and twenty female patients, 40-60 years old, were observed. Mandibular cortical bone thickness was measured using MI on both sides of the mandible. The average MI score of two groups were then assessed using t-sample independent test. There were significant differences of mandibular bone quality based on mandibular cortical bone thickness measurement using MI between male and female patients (p<0.05). Mandibular bone quality based on cortical bone thickness measurement using MI of male and female patients indicated a significant difference.

  12. Association between cortical thickness and CSF biomarkers in mild cognitive impairment and Alzheimer’s disease

    DEFF Research Database (Denmark)

    Mohades, Sara; Dubois, Jonathan; Parent, Maxime

    Background: The dynamic biomarker hypothesis predicts that fluid biomarker abnormalities precede brain morphological changes observed in AD by many years. However, the link between early CSF abnormalities and late structural changes remains under debate. Here we investigated the association between...... between cortical thinning, amyloidosis or tau hyperphosphorylation depends on cortical regions and clinical stages of AD. Methods: T1-weighed MRIs and associated CSF markers from individuals with mild cognitive impairment (MCI; 16), Alzheimer Disease (AD; n¼7) and age-matched cognitively normal subjects...

  13. Differential longitudinal changes in cortical thickness, surface area and volume across the adult life span: regions of accelerating and decelerating change.

    Science.gov (United States)

    Storsve, Andreas B; Fjell, Anders M; Tamnes, Christian K; Westlye, Lars T; Overbye, Knut; Aasland, Hilde W; Walhovd, Kristine B

    2014-06-18

    Human cortical thickness and surface area are genetically independent, emerge through different neurobiological events during development, and are sensitive to different clinical conditions. However, the relationship between changes in the two over time is unknown. Additionally, longitudinal studies have almost invariably been restricted to older adults, precluding the delineation of adult life span trajectories of change in cortical structure. In this longitudinal study, we investigated changes in cortical thickness, surface area, and volume after an average interval of 3.6 years in 207 well screened healthy adults aged 23-87 years. We hypothesized that the relationships among metrics are dynamic across the life span, that the primary contributor to cortical volume reductions in aging is cortical thinning, and that magnitude of change varies with age and region. Changes over time were seen in cortical area (mean annual percentage change [APC], -0.19), thickness (APC, -0.35), and volume (APC, -0.51) in most regions. Volume changes were primarily explained by changes in thickness rather than area. A negative relationship between change in thickness and surface area was found across several regions, where more thinning was associated with less decrease in area, and vice versa. Accelerating changes with increasing age was seen in temporal and occipital cortices. In contrast, decelerating changes were seen in prefrontal and anterior cingulate cortices. In conclusion, a dynamic relationship between cortical thickness and surface area changes exists throughout the adult life span. The mixture of accelerating and decelerating changes further demonstrates the importance of studying these metrics across the entire adult life span. Copyright © 2014 the authors 0270-6474/14/348488-11$15.00/0.

  14. Neonatal pain-related stress predicts cortical thickness at age 7 years in children born very preterm.

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    Manon Ranger

    Full Text Available Altered brain development is evident in children born very preterm (24-32 weeks gestational age, including reduction in gray and white matter volumes, and thinner cortex, from infancy to adolescence compared to term-born peers. However, many questions remain regarding the etiology. Infants born very preterm are exposed to repeated procedural pain-related stress during a period of very rapid brain development. In this vulnerable population, we have previously found that neonatal pain-related stress is associated with atypical brain development from birth to term-equivalent age. Our present aim was to evaluate whether neonatal pain-related stress (adjusted for clinical confounders of prematurity is associated with altered cortical thickness in very preterm children at school age.42 right-handed children born very preterm (24-32 weeks gestational age followed longitudinally from birth underwent 3-D T1 MRI neuroimaging at mean age 7.9 yrs. Children with severe brain injury and major motor/sensory/cognitive impairment were excluded. Regional cortical thickness was calculated using custom developed software utilizing FreeSurfer segmentation data. The association between neonatal pain-related stress (defined as the number of skin-breaking procedures accounting for clinical confounders (gestational age, illness severity, infection, mechanical ventilation, surgeries, and morphine exposure, was examined in relation to cortical thickness using constrained principal component analysis followed by generalized linear modeling.After correcting for multiple comparisons and adjusting for neonatal clinical factors, greater neonatal pain-related stress was associated with significantly thinner cortex in 21/66 cerebral regions (p-values ranged from 0.00001 to 0.014, predominately in the frontal and parietal lobes.In very preterm children without major sensory, motor or cognitive impairments, neonatal pain-related stress appears to be associated with thinner cortex

  15. Graph theory analysis of cortical thickness networks in adolescents with d-transposition of the great arteries.

    Science.gov (United States)

    Watson, Christopher G; Stopp, Christian; Newburger, Jane W; Rivkin, Michael J

    2018-02-01

    Adolescents with d-transposition of the great arteries (d-TGA) who had the arterial switch operation in infancy have been found to have structural brain differences compared to healthy controls. We used cortical thickness measurements obtained from structural brain MRI to determine group differences in global brain organization using a graph theoretical approach. Ninety-two d-TGA subjects and 49 controls were scanned using one of two identical 1.5-Tesla MRI systems. Mean cortical thickness was obtained from 34 regions per hemisphere using Freesurfer. A linear model was used for each brain region to adjust for subject age, sex, and scanning location. Structural connectivity for each group was inferred based on the presence of high inter-regional correlations of the linear model residuals, and binary connectivity matrices were created by thresholding over a range of correlation values for each group. Graph theory analysis was performed using packages in R. Permutation tests were performed to determine significance of between-group differences in global network measures. Within-group connectivity patterns were qualitatively different between groups. At lower network densities, controls had significantly more long-range connections. The location and number of hub regions differed between groups: controls had a greater number of hubs at most network densities. The control network had a significant rightward asymmetry compared to the d-TGA group at all network densities. Using graph theory analysis of cortical thickness correlations, we found differences in brain structural network organization among d-TGA adolescents compared to controls. These may be related to the white matter and gray matter differences previously found in this cohort, and in turn may be related to the cognitive deficits this cohort presents.

  16. Associations between Children's Socioeconomic Status and Prefrontal Cortical Thickness

    Science.gov (United States)

    Lawson, Gwendolyn M.; Duda, Jeffrey T.; Avants, Brian B.; Wu, Jue; Farah, Martha J.

    2013-01-01

    Childhood socioeconomic status (SES) predicts executive function performance and measures of prefrontal cortical function, but little is known about its anatomical correlates. Structural MRI and demographic data from a sample of 283 healthy children from the NIH MRI Study of Normal Brain Development were used to investigate the relationship…

  17. Cortical thickness, surface area, and folding alterations in male youths with conduct disorder and varying levels of callous-unemotional traits.

    Science.gov (United States)

    Fairchild, Graeme; Toschi, Nicola; Hagan, Cindy C; Goodyer, Ian M; Calder, Andrew J; Passamonti, Luca

    2015-01-01

    Previous studies have reported changes in gray matter volume in youths with conduct disorder (CD), although these differences are difficult to interpret as they may have been driven by alterations in cortical thickness, surface area (SA), or folding. The objective of this study was to use surface-based morphometry (SBM) methods to compare male youths with CD and age and sex-matched healthy controls (HCs) in cortical thickness, SA, and folding. We also tested for structural differences between the childhood-onset and adolescence-onset subtypes of CD and performed regression analyses to assess for relationships between CD symptoms and callous-unemotional (CU) traits and SBM-derived measures. We acquired structural neuroimaging data from 20 HCs and 36 CD participants (18 with childhood-onset CD and 18 with adolescence-onset CD) and analyzed the data using FreeSurfer. Relative to HCs, youths with CD showed reduced cortical thickness in the superior temporal gyrus, reduced SA in the orbitofrontal cortex (OFC), and increased cortical folding in the insula. There were no significant differences between the childhood-onset and adolescence-onset CD subgroups in cortical thickness or SA, but several frontal and temporal regions showed increased cortical folding in childhood-onset relative to adolescence-onset CD participants. Both CD subgroups also showed increased cortical folding relative to HCs. CD symptoms were negatively correlated with OFC SA whereas CU traits were positively correlated with insula folding. Cortical thinning in the superior temporal gyrus may contribute to the social cognitive impairments displayed by youths with CD, whereas reduced OFC SA may lead to impairments in emotion regulation and reward processing in youths with CD. The increased cortical folding observed in the insula may reflect a maturational delay in this region and could mediate the link between CU traits and empathy deficits. Altered cortical folding was observed in childhood-onset and

  18. Postnatal Changes in Humerus Cortical Bone Thickness Reflect the Development of Metabolic Bone Disease in Preterm Infants

    Directory of Open Access Journals (Sweden)

    Shuko Tokuriki

    2016-01-01

    Full Text Available Objective. To use cortical bone thickness (CBT of the humerus to identify risk factors for the development of metabolic bone disease in preterm infants. Methods. Twenty-seven infants born at <32 weeks of gestational age, with a birth weight of <1,500 g, were enrolled. Humeral CBT was measured from chest radiographs at birth and at 27-28, 31-32, and 36–44 weeks of postmenstrual age (PMA. The risk factors for the development of osteomalacia were statistically analyzed. Results. The humeral CBT at 36–44 weeks of PMA was positively correlated with gestational age and birth weight and negatively correlated with the duration of mechanical ventilation. CBT increased with PMA, except in six very early preterm infants in whom it decreased. Based on logistic regression analysis, gestational age and duration of mechanical ventilation were identified as risk factors for cortical bone thinning. Conclusions. Humeral CBT may serve as a radiologic marker of metabolic bone disease at 36–44 weeks of PMA in preterm infants. Cortical bones of extremely preterm infants are fragile, even when age is corrected for term, and require extreme care to lower the risk of fractures.

  19. Age- and gender-related regional variations of human brain cortical thickness, complexity, and gradient in the third decade.

    Science.gov (United States)

    Creze, Maud; Versheure, Leslie; Besson, Pierre; Sauvage, Chloe; Leclerc, Xavier; Jissendi-Tchofo, Patrice

    2014-06-01

    Brain functional and cytoarchitectural maturation continue until adulthood, but little is known about the evolution of the regional pattern of cortical thickness (CT), complexity (CC), and intensity or gradient (CG) in young adults. We attempted to detect global and regional age- and gender-related variations of brain CT, CC, and CG, in 28 healthy young adults (19-33 years) using a three-dimensional T1 -weighted magnetic resonance imaging sequence and surface-based methods. Whole brain interindividual variations of CT and CG were similar to that in the literature. As a new finding, age- and gender-related variations significantly affected brain complexity (P middle temporal cortices (age), and the fronto-orbital cortex (gender), all in the right hemisphere. Regions of interest analyses showed age and gender significant interaction (P middle temporal-entorrhinal cortices bilaterally, as well as left inferior parietal. In addition, we found significant inverse correlations between CT and CC and between CT and CG over the whole brain and markedly in precentral and occipital areas. Our findings differ in details from previous reports and may correlate with late brain maturation and learning plasticity in young adults' brain in the third decade. Copyright © 2013 Wiley Periodicals, Inc.

  20. Longitudinal development of frontoparietal activity during feedback learning: Contributions of age, performance, working memory and cortical thickness

    Directory of Open Access Journals (Sweden)

    Sabine Peters

    2016-06-01

    Full Text Available Feedback learning is a crucial skill for cognitive flexibility that continues to develop into adolescence, and is linked to neural activity within a frontoparietal network. Although it is well conceptualized that activity in the frontoparietal network changes during development, there is surprisingly little consensus about the direction of change. Using a longitudinal design (N = 208, 8–27 years, two measurements in two years, we investigated developmental trajectories in frontoparietal activity during feedback learning. Our first aim was to test for linear and nonlinear developmental trajectories in dorsolateral prefrontal cortex (DLPFC, superior parietal cortex (SPC, supplementary motor area (SMA and anterior cingulate cortex (ACC. Second, we tested which factors (task performance, working memory, cortical thickness explained additional variance in time-related changes in activity besides age. Developmental patterns for activity in DLPFC and SPC were best characterized by a quadratic age function leveling off/peaking in late adolescence. There was a linear increase in SMA and a linear decrease with age in ACC activity. In addition to age, task performance explained variance in DLPFC and SPC activity, whereas cortical thickness explained variance in SMA activity. Together, these findings provide a novel perspective of linear and nonlinear developmental changes in the frontoparietal network during feedback learning.

  1. Normalization of cortical thickness measurements across different T1 magnetic resonance imaging protocols by novel W-Score standardization.

    Science.gov (United States)

    Chung, Jinyong; Yoo, Kwangsun; Lee, Peter; Kim, Chan Mi; Roh, Jee Hoon; Park, Ji Eun; Kim, Sang Joon; Seo, Sang Won; Shin, Jeong-Hyeon; Seong, Joon-Kyung; Jeong, Yong

    2017-10-01

    The use of different 3D T1-weighted magnetic resonance (T1 MR) imaging protocols induces image incompatibility across multicenter studies, negating the many advantages of multicenter studies. A few methods have been developed to address this problem, but significant image incompatibility still remains. Thus, we developed a novel and convenient method to improve image compatibility. W-score standardization creates quality reference values by using a healthy group to obtain normalized disease values. We developed a protocol-specific w-score standardization to control the protocol effect, which is applied to each protocol separately. We used three data sets. In dataset 1, brain T1 MR images of normal controls (NC) and patients with Alzheimer's disease (AD) from two centers, acquired with different T1 MR protocols, were used (Protocol 1 and 2, n = 45/group). In dataset 2, data from six subjects, who underwent MRI with two different protocols (Protocol 1 and 2), were used with different repetition times, echo times, and slice thicknesses. In dataset 3, T1 MR images from a large number of healthy normal controls (Protocol 1: n = 148, Protocol 2: n = 343) were collected for w-score standardization. The protocol effect and disease effect on subjects' cortical thickness were analyzed before and after the application of protocol-specific w-score standardization. As expected, different protocols resulted in differing cortical thickness measurements in both NC and AD subjects. Different measurements were obtained for the same subject when imaged with different protocols. Multivariate pattern difference between measurements was observed between the protocols. Classification accuracy between two protocols was nearly 90%. After applying protocol-specific w-score standardization, the differences between the protocols substantially decreased. Most importantly, protocol-specific w-score standardization reduced both univariate and multivariate differences in the images while

  2. Perceived stress is associated with increased rostral middle frontal gyrus cortical thickness: a family-based and discordant-sibling investigation.

    Science.gov (United States)

    Michalski, L J; Demers, C H; Baranger, D A A; Barch, D M; Harms, M P; Burgess, G C; Bogdan, R

    2017-11-01

    Elevated stress perception and depression commonly co-occur, suggesting that they share a common neurobiology. Cortical thickness of the rostral middle frontal gyrus (RMFG), a region critical for executive function, has been associated with depression- and stress-related phenotypes. Here, we examined whether RMFG cortical thickness is associated with these phenotypes in a large family-based community sample. RMFG cortical thickness was estimated using FreeSurfer among participants (n = 879) who completed the ongoing Human Connectome Project. Depression-related phenotypes (i.e. sadness, positive affect) and perceived stress were assessed via self-report. After accounting for sex, age, ethnicity, average whole-brain cortical thickness, twin status and familial structure, RMFG thickness was positively associated with perceived stress and sadness and negatively associated with positive affect at small effect sizes (accounting for 0.2-2.4% of variance; p-fdr: 0.0051-0.1900). Perceived stress was uniquely associated with RMFG thickness after accounting for depression-related phenotypes. Further, among siblings discordant for perceived stress, those reporting higher perceived stress had increased RMFG thickness (P = 4 × 10-7 ). Lastly, RMFG thickness, perceived stress, depressive symptoms, and positive affect were all significantly heritable, with evidence of shared genetic and environmental contributions between self-report measures. Stress perception and depression share common genetic, environmental, and neural correlates. Variability in RMFG cortical thickness may play a role in stress-related depression, although effects may be small in magnitude. Prospective studies are required to examine whether variability in RMFG thickness may function as a risk factor for stress exposure and/or perception, and/or arises as a consequence of these phenotypes. © 2017 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

  3. Cortical thickness and hippocampal shape in pure vascular mild cognitive impairment and dementia of subcortical type.

    Science.gov (United States)

    Kim, H J; Ye, B S; Yoon, C W; Noh, Y; Kim, G H; Cho, H; Jeon, S; Lee, J M; Kim, J-H; Seong, J-K; Kim, C-H; Choe, Y S; Lee, K H; Kim, S T; Kim, J S; Park, S E; Kim, J-H; Chin, J; Cho, J; Kim, C; Lee, J H; Weiner, M W; Na, D L; Seo, S W

    2014-05-01

    The progression pattern of brain structural changes in patients with isolated cerebrovascular disease (CVD) remains unclear. To investigate the role of isolated CVD in cognitive impairment patients, patterns of cortical thinning and hippocampal atrophy in pure subcortical vascular mild cognitive impairment (svMCI) and pure subcortical vascular dementia (SVaD) patients were characterized. Forty-five patients with svMCI and 46 patients with SVaD who were negative on Pittsburgh compound B (PiB) positron emission tomography imaging and 75 individuals with normal cognition (NC) were recruited. Compared with NC, patients with PiB(-) svMCI exhibited frontal, language and retrieval type memory dysfunctions, which in patients with PiB(-) SVaD were further impaired and accompanied by visuospatial and recognition memory dysfunctions. Compared with NC, patients with PiB(-) svMCI exhibited cortical thinning in the frontal, perisylvian, basal temporal and posterior cingulate regions. This atrophy was more prominent and extended further toward the lateral parietal and medial temporal regions in patients with PiB(-) SVaD. Compared with NC subjects, patients with PiB(-) svMCI exhibited hippocampal shape deformities in the lateral body, whilst patients with PiB(-) SVaD exhibited additional deformities within the lateral head and inferior body. Our findings suggest that patients with CVD in the absence of Alzheimer's disease pathology can be demented, showing cognitive impairment in multiple domains, which is consistent with the topography of cortical thinning and hippocampal shape deformity. © 2014 The Author(s) European Journal of Neurology © 2014 EFNS.

  4. Alterations in cortical thickness and neuronal density in the frontal cortex of Albert Einstein.

    Science.gov (United States)

    Anderson, B; Harvey, T

    1996-06-07

    Neuronal density, neuron size, and the number of neurons under 1 mm2 of cerebral cortical surface area were measured in the right pre-frontal cortex of Albert Einstein and five elderly control subjects. Measurement of neuronal density used the optical dissector technique on celloidin-embedded cresyl violet-stained sections. The neurons counted provided a systematic random sample for the measurement of cell body cross-sectional area. Einstein's cortex did not differ from the control subjects in the number of neurons under 1 mm2 of cerebral cortex or in mean neuronal size. Because Einstein's cortex was thinner than the controls he had a greater neuronal density.

  5. A Prospective, Longitudinal Study of the Effect of Remission on Cortical Thickness and Hippocampal Volume in Patients with Treatment-Resistant Depression.

    Science.gov (United States)

    Phillips, Jennifer L; Batten, Lisa A; Tremblay, Philippe; Aldosary, Fahad; Blier, Pierre

    2015-03-30

    Magnetic resonance imaging studies have provided evidence of structural modifications in cortical-limbic regions in major depressive disorder. To date, however, few studies have tracked structural changes in patients during treatment. This prospective, longitudinal imaging study investigated associations between brain structure and clinical responsiveness in a sample of patients with treatment-resistant major depressive disorder during an approximate 1-year follow-up period. FreeSurfer software was used to extract volume or cortical thickness values from 6 regions of interest (hippocampus, rostral middle frontal gyrus, orbitofrontal cortex, rostral and caudal anterior cingulate cortices, and inferior temporal gyrus) in patients (n = 26) and matched healthy controls (n = 28). Regions of interest were selected based on previous evidence of potential associations between morphometric characteristics in these regions and treatment response or remission. Analyses were conducted to compare volume and cortical thickness in patients and controls at baseline imaging, determine whether patients' brain structure at treatment initiation was associated with response over follow-up, and compare longitudinal changes in volume and cortical thickness in patients who achieved sustained 6-month remission (Montgomery-Åsberg Depression Rating Scale Score ≤12) with nonremitters. Patients and controls showed no structural differences at baseline. Among patients, thicker right caudal anterior cingulate cortex at baseline was associated with greater symptom improvement over follow-up. Remitters and nonremitters showed subtle changes in volume and thickness over time in opposing directions, with increased hippocampal volume and cortical thickness in the rostral middle frontal gyrus, orbitofrontal cortex, and inferior temporal gyrus in remitters, and decreased volume or thickness in these regions in nonremitters. The results suggest that longitudinal structural trajectories may differ in

  6. Head-to-head comparison of two popular cortical thickness extraction algorithms: a cross-sectional and longitudinal study.

    Directory of Open Access Journals (Sweden)

    Alberto Redolfi

    Full Text Available The measurement of cortical shrinkage is a candidate marker of disease progression in Alzheimer's. This study evaluated the performance of two pipelines: Civet-CLASP (v1.1.9 and Freesurfer (v5.3.0.Images from 185 ADNI1 cases (69 elderly controls (CTR, 37 stable MCI (sMCI, 27 progressive MCI (pMCI, and 52 Alzheimer (AD patients scanned at baseline, month 12, and month 24 were processed using the two pipelines and two interconnected e-infrastructures: neuGRID (https://neugrid4you.eu and VIP (http://vip.creatis.insa-lyon.fr. The vertex-by-vertex cross-algorithm comparison was made possible applying the 3D gradient vector flow (GVF and closest point search (CPS techniques.The cortical thickness measured with Freesurfer was systematically lower by one third if compared to Civet's. Cross-sectionally, Freesurfer's effect size was significantly different in the posterior division of the temporal fusiform cortex. Both pipelines were weakly or mildly correlated with the Mini Mental State Examination score (MMSE and the hippocampal volumetry. Civet differed significantly from Freesurfer in large frontal, parietal, temporal and occipital regions (p<0.05. In a discriminant analysis with cortical ROIs having effect size larger than 0.8, both pipelines gave no significant differences in area under the curve (AUC. Longitudinally, effect sizes were not significantly different in any of the 28 ROIs tested. Both pipelines weakly correlated with MMSE decay, showing no significant differences. Freesurfer mildly correlated with hippocampal thinning rate and differed in the supramarginal gyrus, temporal gyrus, and in the lateral occipital cortex compared to Civet (p<0.05. In a discriminant analysis with ROIs having effect size larger than 0.6, both pipelines yielded no significant differences in the AUC.Civet appears slightly more sensitive to the typical AD atrophic pattern at the MCI stage, but both pipelines can accurately characterize the topography of cortical

  7. An in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: an axial positioned dynamic compression plate and two abaxial transarticular cortical screws inserted in lag fashion versus three parallel transarticular cortical screws inserted in lag fashion.

    Science.gov (United States)

    Sod, Gary A; Riggs, Laura M; Mitchell, Colin F; Hubert, Jeremy D; Martin, George S

    2010-01-01

    To compare in vitro monotonic biomechanical properties of an axial 3-hole, 4.5 mm narrow dynamic compression plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (DCP-TLS) with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion (3-TLS) for the equine proximal interphalangeal (PIP) joint arthrodesis. Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints. Cadaveric adult equine forelimbs (n=15 pairs). For each forelimb pair, 1 PIP joint was stabilized with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion and 1 with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion. Five matching pairs of constructs were tested in single cycle to failure under axial compression, 5 construct pairs were tested for cyclic fatigue under axial compression, and 5 construct pairs were tested in single cycle to failure under torsional loading. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05. Mean yield load, yield stiffness, and failure load under axial compression and torsion, single cycle to failure, of the DCP-TLS fixation were significantly greater than those of the 3-TLS fixation. Mean cycles to failure in axial compression of the DCP-TLS fixation was significantly greater than that of the 3-TLS fixation. The DCP-TLS was superior to the 3-TLS in resisting the static overload forces and in resisting cyclic fatigue. The results of this in vitro study may provide information to aid in the selection of a treatment modality for arthrodesis of the equine PIP joint.

  8. Strategy-based reasoning training modulates cortical thickness and resting-state functional connectivity in adults with chronic traumatic brain injury.

    Science.gov (United States)

    Han, Kihwan; Davis, Rebecca A; Chapman, Sandra B; Krawczyk, Daniel C

    2017-05-01

    Prior studies have demonstrated training-induced changes in the healthy adult brain. Yet, it remains unclear how the injured brain responds to cognitive training months-to-years after injury. Sixty individuals with chronic traumatic brain injury (TBI) were randomized into either strategy-based (N = 31) or knowledge-based (N = 29) training for 8 weeks. We measured cortical thickness and resting-state functional connectivity (rsFC) before training, immediately posttraining, and 3 months posttraining. Relative to the knowledge-based training group, the cortical thickness of the strategy-based training group showed diverse temporal patterns of changes over multiple brain regions (pvertex training group induced only monotonic increases in connectivity, relative to the knowledge-based training group (|Z| > 1.96, pNBS training group yielded monotonic improvement in scores for the trail-making test (p brain-behavior relationships revealed that improvement in trail-making scores were associated with training-induced changes in cortical thickness (pvertex training group. These findings suggest that training-induced brain plasticity continues through chronic phases of TBI and that brain connectivity and cortical thickness may serve as markers of plasticity.

  9. Comparison of interradicular distances and cortical bone thickness in Thai patients with Class I and Class II skeletal patterns using cone-beam computed tomography.

    Science.gov (United States)

    Khumsarn, Nattida; Patanaporn, Virush; Janhom, Apirum; Jotikasthira, Dhirawat

    2016-06-01

    This study evaluated and compared interradicular distances and cortical bone thickness in Thai patients with Class I and Class II skeletal patterns, using cone-beam computed tomography (CBCT). Pretreatment CBCT images of 24 Thai orthodontic patients with Class I and Class II skeletal patterns were included in the study. Three measurements were chosen for investigation: the mesiodistal distance between the roots, the width of the buccolingual alveolar process, and buccal cortical bone thickness. All distances were recorded at five different levels from the cementoenamel junction (CEJ). Descriptive statistical analysis and t-tests were performed, with the significance level for all tests set at pskeletal pattern showed significantly greater maxillary mesiodistal distances (between the first and second premolars) and widths of the buccolingual alveolar process (between the first and second molars) than Class I skeletal pattern patients at 10 mm above the CEJ. The maxillary buccal cortical bone thicknesses between the second premolar and first molar at 8 mm above the CEJ in Class II patients were likewise significantly greater than in Class I patients. Patients with a Class I skeletal pattern showed significantly wider mandibular buccolingual alveolar processes than did Class II patients (between the first and second molars) at 4, 6, and 8 mm below the CEJ. In both the maxilla and mandible, the mesiodistal distances, the width of the buccolingual alveolar process, and buccal cortical bone thickness tended to increase from the CEJ to the apex in both Class I and Class II skeletal patterns.

  10. Brain surface anatomy in adults with autism: the relationship between surface area, cortical thickness, and autistic symptoms.

    Science.gov (United States)

    Ecker, Christine; Ginestet, Cedric; Feng, Yue; Johnston, Patrick; Lombardo, Michael V; Lai, Meng-Chuan; Suckling, John; Palaniyappan, Lena; Daly, Eileen; Murphy, Clodagh M; Williams, Steven C; Bullmore, Edward T; Baron-Cohen, Simon; Brammer, Michael; Murphy, Declan G M

    2013-01-01

    Neuroimaging studies of brain anatomy in autism spectrum disorder (ASD) have mostly been based on measures of cortical volume (CV). However, CV is a product of 2 distinct parameters, cortical thickness (CT) and surface area (SA), that in turn have distinct genetic and developmental origins. To investigate regional differences in CV, SA, and CT as well as their relationship in a large and well-characterized sample of men with ASD and matched controls. Multicenter case-control design using quantitative magnetic resonance imaging. Medical Research Council UK Autism Imaging Multicentre Study. A total of 168 men, 84 diagnosed as having ASD and 84 controls who did not differ significantly in mean (SD) age (26 [7] years vs 28 [6] years, respectively) or full-scale IQ (110 [14] vs 114 [12], respectively). Between-group differences in CV, SA, and CT investigated using a spatially unbiased vertex-based approach; the degree of spatial overlap between the differences in CT and SA; and their relative contribution to differences in regional CV. Individuals with ASD differed from controls in all 3 parameters. These mainly consisted of significantly increased CT within frontal lobe regions and reduced SA in the orbitofrontal cortex and posterior cingulum. These differences in CT and SA were paralleled by commensurate differences in CV. The spatially distributed patterns for CT and SA were largely nonoverlapping and shared only about 3% of all significantly different locations on the cerebral surface. Individuals with ASD have significant differences in CV, but these may be underpinned by (separable) variations in its 2 components, CT and SA. This is of importance because both measures result from distinct developmental pathways that are likely modulated by different neurobiological mechanisms. This finding may provide novel targets for future studies into the etiology of the condition and a new way to fractionate the disorder.

  11. High thickness histological sections as alternative to study the three-dimensional microscopic human sub-cortical neuroanatomy.

    Science.gov (United States)

    Alho, Eduardo Joaquim Lopes; Alho, Ana Tereza Di Lorenzo; Grinberg, Lea; Amaro, Edson; Dos Santos, Gláucia Aparecida Bento; da Silva, Rafael Emídio; Neves, Ricardo Caires; Alegro, Maryana; Coelho, Daniel Boari; Teixeira, Manoel Jacobsen; Fonoff, Erich Talamoni; Heinsen, Helmut

    2017-11-01

    Stereotaxy is based on the precise image-guided spatial localization of targets within the human brain. Even with the recent advances in MRI technology, histological examination renders different (and complementary) information of the nervous tissue. Although several maps have been selected as a basis for correlating imaging results with the anatomical locations of sub-cortical structures, technical limitations interfere in a point-to-point correlation between imaging and anatomy due to the lack of precise correction for post-mortem tissue deformations caused by tissue fixation and processing. We present an alternative method to parcellate human brain cytoarchitectural regions, minimizing deformations caused by post-mortem and tissue-processing artifacts and enhancing segmentation by means of modified high thickness histological techniques and registration with MRI of the same specimen and into MNI space (ICBM152). A three-dimensional (3D) histological atlas of the human thalamus, basal ganglia, and basal forebrain cholinergic system is displayed. Structure's segmentations were performed in high-resolution dark-field and light-field microscopy. Bidimensional non-linear registration of the histological slices was followed by 3D registration with in situ MRI of the same subject. Manual and automated registration procedures were adopted and compared. To evaluate the quality of the registration procedures, Dice similarity coefficient and normalized weighted spectral distance were calculated and the results indicate good overlap between registered volumes and a small shape difference between them in both manual and automated registration methods. High thickness high-resolution histological slices in combination with registration to in situ MRI of the same subject provide an effective alternative method to study nuclear boundaries in the human brain, enhancing segmentation and demanding less resources and time for tissue processing than traditional methods.

  12. Cortical thickness and VBM in young women at risk for familial depression and their depressed mothers with positive family history.

    Science.gov (United States)

    Ozalay, Ozgun; Aksoy, Burcu; Tunay, Sebnem; Simsek, Fatma; Chandhoki, Swati; Kitis, Omer; Eker, Cagdas; Gonul, Ali Saffet

    2016-06-30

    It has been demonstrated that compared to low-risk subjects, high-risk subjects for depression have structural and functional alterations in their brain scans even before the disease onset. However, it is not known if these alterations are related to vulnerability to depression or epiphenomena. One way to resolve this ambiguity is to detect the structural alterations in the high-risk subjects and determine if the same alterations are present in the probands. In this study, we recruited 24 women with the diagnosis of Major Depressive Disorder (MDD) with recurrent episodes and their healthy daughters (the high-risk for familial depression group; HRFD). We compared structural brain scans of the patients and HRFG group with those of 24 age-matched healthy mothers and their healthy daughters at similar ages to the HRFD group; respectively. Both cortical gray matter (GM) volume and thickness analyses revealed that HRFD daughters and their MDD mothers had similar GM differences in two regions: the right temporoparietal region and the dorsomedial prefrontal cortex. These results suggested that the observed alterations may be related to trait clinical and neurophysiological characteristics of MDD and may present before the onset of illness. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. The Influence of High-Impact Exercise on Cortical and Trabecular Bone Mineral Content and 3D Distribution Across the Proximal Femur in Older Men: A Randomized Controlled Unilateral Intervention.

    Science.gov (United States)

    Allison, Sarah J; Poole, Kenneth E S; Treece, Graham M; Gee, Andrew H; Tonkin, Carol; Rennie, Winston J; Folland, Jonathan P; Summers, Gregory D; Brooke-Wavell, Katherine

    2015-09-01

    Regular exercisers have lower fracture risk, despite modest effects of exercise on bone mineral content (BMC). Exercise may produce localized cortical and trabecular bone changes that affect bone strength independently of BMC. We previously demonstrated that brief, daily unilateral hopping exercises increased femoral neck BMC in the exercise leg versus the control leg of older men. This study evaluated the effects of these exercises on cortical and trabecular bone and its 3D distribution across the proximal femur, using clinical CT. Fifty healthy men had pelvic CT scans before and after the exercise intervention. We used hip QCT analysis to quantify BMC in traditional regions of interest and estimate biomechanical variables. Cortical bone mapping localized cortical mass surface density and endocortical trabecular density changes across each proximal femur, which involved registration to a canonical proximal femur model. Following statistical parametric mapping, we visualized and quantified statistically significant changes of variables over time in both legs, and significant differences between legs. Thirty-four men aged mean (SD) 70 (4) years exercised for 12-months, attending 92% of prescribed sessions. In traditional regions of interest, cortical and trabecular BMC increased over time in both legs. Cortical BMC at the trochanter increased more in the exercise than control leg, whereas femoral neck buckling ratio declined more in the exercise than control leg. Across the entire proximal femur, cortical mass surface density increased significantly with exercise (2.7%; p 6%) at anterior and posterior aspects of the femoral neck and anterior shaft. Endocortical trabecular density also increased (6.4%; p 12% at the anterior femoral neck, trochanter, and inferior femoral head. Odd impact exercise increased cortical mass surface density and endocortical trabecular density, at regions that may be important to structural integrity. These exercise-induced changes were

  14. Low-frequency axial ultrasound velocity correlates with bone mineral density and cortical thickness in the radius and tibia in pre- and postmenopausal women.

    Science.gov (United States)

    Kilappa, V; Moilanen, P; Xu, L; Nicholson, P H F; Timonen, J; Cheng, S

    2011-04-01

    Axial transmission velocity of a low-frequency first arriving signal (V (LF)) was assessed in the radius and tibia of 254 females, and compared to site-matched pQCT measurements. V (LF) best correlated with cortical BMD, but significantly also with subcortical BMD and cortical thickness. Correlations were strongest for the radius in postmenopausal females. Ultrasonic low-frequency (LF; 0.2-0.4 MHz) axial transmission, based on the first arriving signal (FAS), provides enhanced sensitivity to thickness and endosteal properties of cortical wall of the radius and tibia compared to using higher frequencies (e.g., 1 MHz). This improved sensitivity of the LF approach has not yet been clearly confirmed by an in vivo study on adult subjects. The aims of the present study were to evaluate the extent to which LF measurements reflect cortical thickness and bone mineral density, and to assess whether an individual LF measurement can provide a useful estimate for these bone properties. Velocity of the LF FAS (V (LF)) was assessed in the radius and tibia shaft by a new ultrasonometer (CV(RMS) = 0.5%) in a cross-sectional study involving 159 premenopausal (20-58 years) and 95 postmenopausal females (45-88 years). Site-matched volumetric total bone mineral density (BMD), cortical bone mineral density (CBMD), subcortical bone mineral density (ScBMD) and cortical thickness (CTh) were assessed using pQCT. For the postmenopausal females, V (LF) correlated best with CBMD in the radius (R = 0.850, p < 0.001), but significantly also with ScBMD and CTh (R = 0.759 and R = 0.761, respectively; p < 0.001). Similar trends but weaker correlations were observed for the tibia and for the premenopausal women. The LF assessment, with an optimal excitation frequency, thus provided good prediction of both cortical thickness and subcortical bone material properties. These results suggest that the LF approach does indeed have enhanced sensitivity for detecting osteoporotic changes that occur deep in

  15. Interaction between DRD2 and lead exposure on the cortical thickness of the frontal lobe in youth with attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Kim, Johanna Inhyang; Kim, Jae-Won; Lee, Jong-Min; Yun, Hyuk Jin; Sohn, Chul-Ho; Shin, Min-Sup; Kim, Bongseog; Chae, Jonghee; Roh, Jaewoo; Kim, Bung-Nyun

    2018-03-02

    The dopamine receptor D2 receptor (DRD2) gene and lead exposure are both thought to contribute to the pathophysiology of attention-deficit/hyperactivity disorder (ADHD). ADHD is characterized by delay in brain maturation, most prominent in the prefrontal cortex (PFC). The D2 receptor is also mainly located in the PFC, and animal studies show that lead exposure affects the dopaminergic system of the frontal lobe, indicating an overlap in neural correlates of ADHD, DRD2, and lead exposure. We examined the interaction effects of DRD2 rs1800497 and lead exposure on the cortical thickness of the frontal lobe in patients with ADHD. A 1:1 age- and gender-matched sample of 75 participants with ADHD and 75 healthy participants was included in the analysis. The interaction effects of DRD2 and lead exposure on the cortical thickness of 12 regions of interest in the frontal lobe were examined by multivariable linear regression analyses. When we investigated the DRD2×lead effects in the ADHD and HC groups separately, significant DRD2×lead effects were found in the ADHD group, but not in the healthy control group in multiple ROIs of the frontal lobe. There was a significant negative correlation between the cortical thickness of the right superior frontal gyrus and inattention scores. The present findings demonstrated significant interaction effects of DRD2 and lead exposure on the cortical thickness of the frontal lobe in ADHD. Replication studies with larger sample sizes, using a prospective design, are warranted to confirm these findings. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Comparison of interradicular distances and cortical bone thickness in Thai patients with class I and class II skeletal patterns using cone-beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Khumsarn, Nattida [Dental Division of Lamphun Hospital, Lamphun (Thailand); Patanaporn, Virush; Janhom, Apirum; Jotikasthira, Dhirawat [Faculty of Dentistry, Chiang Mai University, Chiang Mai (Thailand)

    2016-06-15

    This study evaluated and compared interradicular distances and cortical bone thickness in Thai patients with Class I and Class II skeletal patterns, using cone-beam computed tomography (CBCT). Pretreatment CBCT images of 24 Thai orthodontic patients with Class I and Class II skeletal patterns were included in the study. Three measurements were chosen for investigation: the mesiodistal distance between the roots, the width of the buccolingual alveolar process, and buccal cortical bone thickness. All distances were recorded at five different levels from the cementoenamel junction (CEJ). Descriptive statistical analysis and t-tests were performed, with the significance level for all tests set at p<0.05. Patients with a Class II skeletal pattern showed significantly greater maxillary mesiodistal distances (between the first and second premolars) and widths of the buccolingual alveolar process (between the first and second molars) than Class I skeletal pattern patients at 10 mm above the CEJ. The maxillary buccal cortical bone thicknesses between the second premolar and first molar at 8 mm above the CEJ in Class II patients were likewise significantly greater than in Class I patients. Patients with a Class I skeletal pattern showed significantly wider mandibular buccolingual alveolar processes than did Class II patients (between the first and second molars) at 4, 6, and 8 mm below the CEJ. In both the maxilla and mandible, the mesiodistal distances, the width of the buccolingual alveolar process, and buccal cortical bone thickness tended to increase from the CEJ to the apex in both Class I and Class II skeletal patterns.

  17. Influence of porosity, pore size, and cortical thickness on the propagation of ultrasonic waves guided through the femoral neck cortex: a simulation study.

    Science.gov (United States)

    Rohde, Kerstin; Rohrbach, Daniel; Glüer, Claus-C; Laugier, Pascal; Grimal, Quentin; Raum, Kay; Barkmann, Reinhard

    2014-02-01

    The femoral neck is a common fracture site in elderly people. The cortical shell is thought to be the major contributor to the mechanical competence of the femoral neck, but its microstructural parameters are not sufficiently accessible under in vivo conditions with current X-ray-based methods. To systematically investigate the influences of pore size, porosity, and thickness of the femoral neck cortex on the propagation of ultrasound, we developed 96 different bone models (combining 6 different pore sizes with 4 different porosities and 4 different thicknesses) and simulated the ultrasound propagation using a finite-difference time-domain algorithm. The simulated single-element emitter and receiver array consisting of 16 elements (8 inferior and 8 superior) were placed at anterior and posterior sides of the bone, respectively (transverse transmission). From each simulation, we analyzed the waveform collected by each of the inferior receiver elements for the one with the shortest time of flight. The first arriving signal of this waveform, which is associated with the wave traveling through the cortical shell, was then evaluated for its three different waveform characteristics (TOF: time point of the first point of inflection of the received signal, Δt: difference between the time point at which the signal first crosses the zero baseline and TOF, and A: amplitude of the first extreme of the first arriving signal). From the analyses of these waveform characteristics, we were able to develop multivariate models to predict pore size, porosity, and cortical thickness, corresponding to the 96 different bone models, with remaining errors in the range of 50 μm for pore size, 1.5% for porosity, and 0.17 mm for cortical thickness.

  18. The impact of ADHD persistence, recent cannabis use, and age of regular cannabis use onset on subcortical volume and cortical thickness in young adults.

    Science.gov (United States)

    Lisdahl, Krista M; Tamm, Leanne; Epstein, Jeffery N; Jernigan, Terry; Molina, Brooke S G; Hinshaw, Stephen P; Swanson, James M; Newman, Erik; Kelly, Clare; Bjork, James M

    2016-04-01

    Both Attention Deficit Hyperactivity Disorder (ADHD) and chronic cannabis (CAN) use have been associated with brain structural abnormalities, although little is known about the effects of both in young adults. Participants included: those with a childhood diagnosis of ADHD who were CAN users (ADHD_CAN; n=37) and non-users (NU) (ADHD_NU; n=44) and a local normative comparison group (LNCG) who did (LNCG_CAN; n=18) and did not (LNCG_NU; n=21) use CAN regularly. Multiple regressions and MANCOVAs were used to examine the independent and interactive effects of a childhood ADHD diagnosis and CAN group status and age of onset (CUO) on subcortical volumes and cortical thickness. After controlling for age, gender, total brain volume, nicotine use, and past-year binge drinking, childhood ADHD diagnosis did not predict brain structure; however, persistence of ADHD was associated with smaller left precentral/postcentral cortical thickness. Compared to all non-users, CAN users had decreased cortical thickness in right hemisphere superior frontal sulcus, anterior cingulate, and isthmus of cingulate gyrus regions and left hemisphere superior frontal sulcus and precentral gyrus regions. Early cannabis use age of onset (CUO) in those with ADHD predicted greater right hemisphere superior frontal and postcentral cortical thickness. Young adults with persistent ADHD demonstrated brain structure abnormalities in regions underlying motor control, working memory and inhibitory control. Further, CAN use was linked with abnormal brain structure in regions with high concentrations of cannabinoid receptors. Additional large-scale longitudinal studies are needed to clarify how substance use impacts neurodevelopment in youth with and without ADHD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. The role of inter-prosthetic distance, cortical thickness and bone mineral density in the development of inter-prosthetic fractures of the femur: a biomechanical cadaver study.

    Science.gov (United States)

    Weiser, L; Korecki, M A; Sellenschloh, K; Fensky, F; Püschel, K; Morlock, M M; Rueger, J M; Lehmann, W

    2014-10-01

    It is becoming increasingly common for a patient to have ipsilateral hip and knee replacements. The inter-prosthetic (IP) distance, the distance between the tips of hip and knee prostheses, has been thought to be associated with an increased risk of IP fracture. Small gap distances are generally assumed to act as stress risers, although there is no real biomechanical evidence to support this. The purpose of this study was to evaluate the influence of IP distance, cortical thickness and bone mineral density on the likelihood of an IP femoral fracture. A total of 18 human femur specimens were randomised into three groups by bone density and cortical thickness. For each group, a defined IP distance of 35 mm, 80 mm or 160 mm was created by choosing the appropriate lengths of component. The maximum fracture strength was determined using a four-point bending test. The fracture force of all three groups was similar (p = 0.498). There was a highly significant correlation between the cortical area and the fracture strength (r = 0.804, p < 0.001), whereas bone density showed no influence. This study suggests that the IP distance has little influence on fracture strength in IP femoral fractures: the thickness of the cortex seems to be the decisive factor. ©2014 The British Editorial Society of Bone & Joint Surgery.

  20. Optimizing finite element predictions of local subchondral bone structural stiffness using neural network-derived density-modulus relationships for proximal tibial subchondral cortical and trabecular bone.

    Science.gov (United States)

    Nazemi, S Majid; Amini, Morteza; Kontulainen, Saija A; Milner, Jaques S; Holdsworth, David W; Masri, Bassam A; Wilson, David R; Johnston, James D

    2017-01-01

    Quantitative computed tomography based subject-specific finite element modeling has potential to clarify the role of subchondral bone alterations in knee osteoarthritis initiation, progression, and pain. However, it is unclear what density-modulus equation(s) should be applied with subchondral cortical and subchondral trabecular bone when constructing finite element models of the tibia. Using a novel approach applying neural networks, optimization, and back-calculation against in situ experimental testing results, the objective of this study was to identify subchondral-specific equations that optimized finite element predictions of local structural stiffness at the proximal tibial subchondral surface. Thirteen proximal tibial compartments were imaged via quantitative computed tomography. Imaged bone mineral density was converted to elastic moduli using multiple density-modulus equations (93 total variations) then mapped to corresponding finite element models. For each variation, root mean squared error was calculated between finite element prediction and in situ measured stiffness at 47 indentation sites. Resulting errors were used to train an artificial neural network, which provided an unlimited number of model variations, with corresponding error, for predicting stiffness at the subchondral bone surface. Nelder-Mead optimization was used to identify optimum density-modulus equations for predicting stiffness. Finite element modeling predicted 81% of experimental stiffness variance (with 10.5% error) using optimized equations for subchondral cortical and trabecular bone differentiated with a 0.5g/cm(3) density. In comparison with published density-modulus relationships, optimized equations offered improved predictions of local subchondral structural stiffness. Further research is needed with anisotropy inclusion, a smaller voxel size and de-blurring algorithms to improve predictions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Cannabis use and progressive cortical thickness loss in areas rich in CB1 receptors during the first five years of schizophrenia.

    Science.gov (United States)

    Rais, Monica; van Haren, Neeltje E M; Cahn, Wiepke; Schnack, Hugo G; Lepage, Claude; Collins, Louis; Evans, Alan C; Hulshoff Pol, Hilleke E; Kahn, René S

    2010-12-01

    Cerebral grey matter volume reductions are progressive in schizophrenia, with larger grey matter volume decreases associated with cannabis use. It is unknown whether this grey matter loss is globally distributed over the entire brain or more pronounced in specific cortical brain regions. Fifty-one patients with recent-onset schizophrenia and 31 matched healthy subjects were included. For all subjects, magnetic resonance imaging scans were obtained at inclusion and at 5-year follow-up. Nineteen patients (ab-)used cannabis but no other illicit drugs; 32 patients and the healthy comparison subjects did not use any drugs during the 5-year follow-up. At follow-up, clinical outcome was measured. To evaluate the local differences in cortical thickness change over five years between the two groups regression analysis was carried out over the cortical surface. At inclusion cortical thickness did not differ between patients and controls and between cannabis-using and non-using patients. Over the follow-up period we found excessive thinning of the right supplementary motor cortex, inferior frontal cortex, superior temporal gyrus, angular gyrus, occipital and parietal lobe in patients relative to controls after controlling for cannabis use. Patients who used cannabis showed additional thinning in the left dorsolateral prefrontal cortex (DLPFC), left anterior cingulate cortex (ACC) and left occipital lobe as compared to those patients that did not use cannabis during the scan interval. First-episode schizophrenia patients who use cannabis show a more pronounced cortical thinning than non-using patients in areas known for their high density of CB1 receptors, such as the ACC and the DLPFC. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Cross-sectional and longitudinal analysis of the relationship between Aβ deposition, cortical thickness, and memory in cognitively unimpaired individuals and in Alzheimer disease.

    Science.gov (United States)

    Doré, Vincent; Villemagne, Victor L; Bourgeat, Pierrick; Fripp, Jurgen; Acosta, Oscar; Chetélat, Gael; Zhou, Luping; Martins, Ralph; Ellis, Kathryn A; Masters, Colin L; Ames, David; Salvado, Oliver; Rowe, Christopher C

    2013-07-01

    β-amyloid (Aβ) deposition is one of the hallmarks of Alzheimer disease. Aβ deposition accelerates gray matter atrophy at early stages of the disease even before objective cognitive impairment is manifested. Identification of at-risk individuals at the presymptomatic stage has become a major research interest because it will allow early therapeutic interventions before irreversible synaptic and neuronal loss occur. We aimed to further characterize the cross-sectional and longitudinal relationship between Aβ deposition, gray matter atrophy, and cognitive impairment. To investigate the topographical relationship of Aβ deposition, gray matter atrophy, and memory impairment in asymptomatic individuals with Alzheimer disease pathology as assessed by Pittsburgh compound B positron emission tomography (PiB-PET). Regional analysis was performed on the cortical surface to relate cortical thickness to PiB retention and episodic memory. The Australian Imaging, Biomarkers, and Lifestyle Study of Aging, Austin Hospital, Melbourne, Australia. Ninety-three healthy elderly control subjects (NCs) and 40 patients with Alzheimer disease from the Australian Imaging, Biomarkers, and Lifestyle Study of Aging cohort. Participants underwent neuropsychological evaluation as well as magnetic resonance imaging and PiB-PET scans. Fifty-four NCs underwent repeated scans and neuropsychological evaluation 18 and 36 months later. Correlations between cortical thickness, PiB retention, and episodic memory. RESULTS There was a significant reduction in cortical thickness in the precuneus and hippocampus associated with episodic memory impairment in the NC PiB-positive (NC+) group when compared with the NC- group. Cortical thickness was also correlated negatively with neocortical PiB in the NC+ group. Longitudinal analysis showed a faster rate of gray matter (GM) atrophy in the temporal lobe and the hippocampi of the NC+ group. Over time, GM atrophy became more extensive in the NC+ group

  3. Higher education is not associated with greater cortical thickness in brain areas related to literacy or intelligence in normal aging or mild cognitive impairment.

    Science.gov (United States)

    Pillai, Jagan A; McEvoy, Linda K; Hagler, Donald J; Holland, Dominic; Dale, Anders M; Salmon, David P; Galasko, Douglas; Fennema-Notestine, Christine

    2012-01-01

    Education may reduce risk of dementia through passive reserve, by increasing neural substrate. We tested the hypotheses that education is associated with thicker cortex and reduced rates of atrophy in brain regions related to literacy and intellectual ability. Healthy older adults and those with mild cognitive impairment were categorized into high (≥18 years) and low (≤13 years) education groups. Higher education was associated with thinner cortices in several areas, but one-year atrophy rates in these areas did not differ by education group. These results do not support a passive reserve model in which early-life education protects against dementia by increasing cortical thickness. Connectivity and synaptic efficiency or other lifestyle factors may more directly reflect cognitive reserve.

  4. Sexual dimorphism of volume reduction but not cognitive deficit in fetal alcohol spectrum disorders: A combined diffusion tensor imaging, cortical thickness and brain volume study

    Directory of Open Access Journals (Sweden)

    Sarah Treit

    2017-01-01

    Full Text Available Quantitative magnetic resonance imaging (MRI has revealed abnormalities in brain volumes, cortical thickness and white matter microstructure in fetal alcohol spectrum disorders (FASD; however, no study has reported all three measures within the same cohort to assess the relative magnitude of deficits, and few studies have examined sex differences. Participants with FASD (n = 70; 30 females; 5–32 years and healthy controls (n = 74; 35 females; 5–32 years underwent cognitive testing and MRI to assess cortical thickness, regional brain volumes and fractional anisotropy (FA/mean diffusivity (MD of white matter tracts. A significant effect of group, age-by-group, or sex-by-group was found for 9/9 volumes, 7/39 cortical thickness regions, 3/9 white matter tracts, and 9/10 cognitive tests, indicating group differences that in some cases differ by age or sex. Volume reductions for several structures were larger in males than females, despite similar deficits of cognition in both sexes. Correlations between brain structure and cognitive scores were found in females of both groups, but were notably absent in males. Correlations within a given MRI modality (e.g. total brain volume and caudate volume were prevalent in both the control and FASD groups, and were more numerous than correlations between measurement types (e.g. volumes and diffusion tensor imaging in either cohort. This multi-modal MRI study finds widespread differences of brain structure in participants with prenatal alcohol exposure, and to a greater extent in males than females which may suggest attenuation of the expected process of sexual dimorphism of brain structure during typical development.

  5. Location of the Mandibular Canal and Thickness of the Occlusal Cortical Bone at Dental Implant Sites in the Lower Second Premolar and First Molar

    Directory of Open Access Journals (Sweden)

    Jui-Ting Hsu

    2013-01-01

    Full Text Available The objective of this study was to evaluate the location of the mandibular canal and the thickness of the occlusal cortical bone at dental implant sites in the lower second premolar and lower first molar by using dental cone-beam computed tomography (CBCT. Seventy-nine sites (47 second premolar and 32 first molar sites were identified in the dental CBCT examinations of 47 patients. In this study, 4 parameters were measured: (1 MC—the distance from the mandibular canal to the upper border of the mandible; (2 CD—the distance from the mandibular canal to the buccal border of the mandible; (3 MD—the distance from the mandibular canal to the lingual border of the mandible; (4 TC—the thickness of the cortical bone at the occlusal side. A statistical analysis was employed to compare the size and differences between these 4 parameters at the lower second premolar and lower first molar. Regarding the MC and MD, the experimental results showed no statistical difference between the first molar and second premolar. However, the TC for the second premolar was greater than that of the first molar. Thus, careful consideration is necessary in choosing the size of and operation type for dental implants.

  6. Evaluation of deep gray matter volume, cortical thickness and white matter integrity in patients with typical absence epilepsy: a study using voxelwise-based techniques

    Energy Technology Data Exchange (ETDEWEB)

    Correa, D.G.; Ventura, N.; Tukamoto, G.; Gasparetto, E.L. [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro (Brazil); Zimmermann, N. [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Pontifical Catholic University of Rio Grande do Sul, Department of Psychology, Porto Alegre (Brazil); Doring, T.M. [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro (Brazil); Leme, J.; Pereira, M. [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Andrea, I. d' ; Rego, C.; Alves-Leon, S.V. [Federal University of Rio de Janeiro, Department of Neurology, Epilepsy Center, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro (Brazil)

    2017-03-15

    The objective of this study was to evaluate the cortical thickness and the volume of deep gray matter structures, measured from 3D T1-weighted gradient echo imaging, and white matter integrity, by diffusion tensor imaging (DTI) in patients with typical absence epilepsy (AE). Patients (n = 19) with typical childhood AE and juvenile AE, currently taking antiepileptic medication, were compared with control subjects (n = 19), matched for gender and age. 3D T1 magnetization-prepared rapid gradient echo-weighted imaging and DTI along 30 noncolinear directions were performed using a 1.5-T MR scanner. FreeSurfer was used to perform cortical volumetric reconstruction and segmentation of deep gray matter structures. For tract-based spatial statistics analysis of DTI, a white matter skeleton was created, along with a permutation-based inference with 5000 permutations. A threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The mean, radial, and axial diffusivities were also projected onto the mean FA skeleton. Patients with AE presented decreased FA and increased mean diffusivity and radial diffusivity values in the genu and the body of the corpus callosum and right anterior corona radiata, as well as decreased axial diffusivity in the left posterior thalamic radiation, inferior cerebellar peduncle, right cerebral peduncle, and right corticospinal tract. However, there were no significant differences in cortical thickness or deep gray matter structure volumes between patients with AE and controls. Abnormalities found in white matter integrity may help to better understand the pathophysiology of AE and optimize diagnosis and treatment strategies. (orig.)

  7. Improved Diagnostic Accuracy of Alzheimer's Disease by Combining Regional Cortical Thickness and Default Mode Network Functional Connectivity: Validated in the Alzheimer's Disease Neuroimaging Initiative Set.

    Science.gov (United States)

    Park, Ji Eun; Park, Bumwoo; Kim, Sang Joon; Kim, Ho Sung; Choi, Choong Gon; Jung, Seung Chai; Oh, Joo Young; Lee, Jae-Hong; Roh, Jee Hoon; Shim, Woo Hyun

    2017-01-01

    To identify potential imaging biomarkers of Alzheimer's disease by combining brain cortical thickness (CThk) and functional connectivity and to validate this model's diagnostic accuracy in a validation set. Data from 98 subjects was retrospectively reviewed, including a study set (n = 63) and a validation set from the Alzheimer's Disease Neuroimaging Initiative (n = 35). From each subject, data for CThk and functional connectivity of the default mode network was extracted from structural T1-weighted and resting-state functional magnetic resonance imaging. Cortical regions with significant differences between patients and healthy controls in the correlation of CThk and functional connectivity were identified in the study set. The diagnostic accuracy of functional connectivity measures combined with CThk in the identified regions was evaluated against that in the medial temporal lobes using the validation set and application of a support vector machine. Group-wise differences in the correlation of CThk and default mode network functional connectivity were identified in the superior temporal (p functional connectivity combined with the CThk of those two regions were more accurate than that combined with the CThk of both medial temporal lobes (91.7% vs. 75%). Combining functional information with CThk of the superior temporal and supramarginal gyri in the left cerebral hemisphere improves diagnostic accuracy, making it a potential imaging biomarker for Alzheimer's disease.

  8. Disparity between dorsal and ventral networks in patients with obsessive-compulsive disorder: Evidence revealed by graph theoretical analysis based on cortical thickness from MRI

    Directory of Open Access Journals (Sweden)

    Seung-Goo eKim

    2013-07-01

    Full Text Available As one of the most widely accepted neuroanatomical models on OCD, it has been hypothesized that imbalance between an excitatory direct (ventral pathway and an inhibitory indirect (dorsal pathway in cortico-striato-thalamic circuit underlies the emergence of OCD. Here we examine the structural network in drug-free patients with OCD in terms of graph theoretical measures for the first time. We used a measure called efficiency which quantifies how a node transfers information efficiently. To construct brain networks, cortical thickness was automatically estimated using T1-weighted magnetic resonance imaging. We found that the network of the OCD patients was as efficient as that of healthy controls so that the both networks were in the small-world regime. More importantly, however, disparity between the dorsal and the ventral networks in the OCD patients was found, suggesting a positive evidence to the imbalance theory on the underlying pathophysiology of OCD.

  9. The effects of FreeSurfer version, workstation type, and Macintosh operating system version on anatomical volume and cortical thickness measurements.

    Directory of Open Access Journals (Sweden)

    Ed H B M Gronenschild

    Full Text Available FreeSurfer is a popular software package to measure cortical thickness and volume of neuroanatomical structures. However, little if any is known about measurement reliability across various data processing conditions. Using a set of 30 anatomical T1-weighted 3T MRI scans, we investigated the effects of data processing variables such as FreeSurfer version (v4.3.1, v4.5.0, and v5.0.0, workstation (Macintosh and Hewlett-Packard, and Macintosh operating system version (OSX 10.5 and OSX 10.6. Significant differences were revealed between FreeSurfer version v5.0.0 and the two earlier versions. These differences were on average 8.8 ± 6.6% (range 1.3-64.0% (volume and 2.8 ± 1.3% (1.1-7.7% (cortical thickness. About a factor two smaller differences were detected between Macintosh and Hewlett-Packard workstations and between OSX 10.5 and OSX 10.6. The observed differences are similar in magnitude as effect sizes reported in accuracy evaluations and neurodegenerative studies.The main conclusion is that in the context of an ongoing study, users are discouraged to update to a new major release of either FreeSurfer or operating system or to switch to a different type of workstation without repeating the analysis; results thus give a quantitative support to successive recommendations stated by FreeSurfer developers over the years. Moreover, in view of the large and significant cross-version differences, it is concluded that formal assessment of the accuracy of FreeSurfer is desirable.

  10. The effects of FreeSurfer version, workstation type, and Macintosh operating system version on anatomical volume and cortical thickness measurements.

    Science.gov (United States)

    Gronenschild, Ed H B M; Habets, Petra; Jacobs, Heidi I L; Mengelers, Ron; Rozendaal, Nico; van Os, Jim; Marcelis, Machteld

    2012-01-01

    FreeSurfer is a popular software package to measure cortical thickness and volume of neuroanatomical structures. However, little if any is known about measurement reliability across various data processing conditions. Using a set of 30 anatomical T1-weighted 3T MRI scans, we investigated the effects of data processing variables such as FreeSurfer version (v4.3.1, v4.5.0, and v5.0.0), workstation (Macintosh and Hewlett-Packard), and Macintosh operating system version (OSX 10.5 and OSX 10.6). Significant differences were revealed between FreeSurfer version v5.0.0 and the two earlier versions. These differences were on average 8.8 ± 6.6% (range 1.3-64.0%) (volume) and 2.8 ± 1.3% (1.1-7.7%) (cortical thickness). About a factor two smaller differences were detected between Macintosh and Hewlett-Packard workstations and between OSX 10.5 and OSX 10.6. The observed differences are similar in magnitude as effect sizes reported in accuracy evaluations and neurodegenerative studies.The main conclusion is that in the context of an ongoing study, users are discouraged to update to a new major release of either FreeSurfer or operating system or to switch to a different type of workstation without repeating the analysis; results thus give a quantitative support to successive recommendations stated by FreeSurfer developers over the years. Moreover, in view of the large and significant cross-version differences, it is concluded that formal assessment of the accuracy of FreeSurfer is desirable.

  11. Correlations between measures of executive attention and cortical thickness of left posterior middle frontal gyrus - a dichotic listening study

    Directory of Open Access Journals (Sweden)

    Lundervold Arvid

    2009-10-01

    Full Text Available Abstract Background The frontal lobe has been associated to a wide range of cognitive control functions and is also vulnerable to degeneration in old age. A recent study by Thomsen and colleagues showed a difference between a young and old sample in grey matter density and activation in the left middle frontal cortex (MFC and performance on a dichotic listening task. The present study investigated this brain behaviour association within a sample of healthy older individuals, and predicted a positive correlation between performance in a condition requiring executive attention and measures of grey matter structure of the posterior left MFC. Methods A dichotic listening forced attention paradigm was used to measure attention control functions. Subjects were instructed to report only the left or the right ear syllable of a dichotically presented consonant-vowel syllable pair. A conflict situation appears when subjects are instructed to report the left ear stimulus, caused by the conflict with the bottom-up, stimulus-driven right ear advantage. Overcoming this processing conflict was used as a measure of executive attention. Thickness and volumes of frontal lobe regions were derived from automated segmentation of 3D magnetic resonance image acquisitions. Results The results revealed a statistically significant positive correlation between the thickness measure of the left posterior MFC and performance on the dichotic listening measures of executive attention. Follow-up analyses showed that this correlation was only statistically significant in the subgroup that showed the typical bottom-up, stimulus-driven right ear advantage. Conclusion The results suggest that the left MFC is a part of an executive attention network, and that the dichotic listening forced attention paradigm may be a feasible tool for assessing subtle attentional dysfunctions in older adults.

  12. Brief communication: Paleobiological inferences on the locomotor repertoire of extinct hominoids based on femoral neck cortical thickness: The fossil great ape hispanopithecus laietanus as a test-case study.

    Science.gov (United States)

    Pina, Marta; Alba, David M; Almécija, Sergio; Fortuny, Josep; Moyà-Solà, Salvador

    2012-09-01

    The relationship between femoral neck superior and inferior cortical thickness in primates is related to locomotor behavior. This relationship has been employed to infer bipedalism in fossil hominins, although bipeds share the same pattern of generalized quadrupeds, where the superior cortex is thinner than the inferior one. In contrast, knuckle-walkers and specialized suspensory taxa display a more homogeneous distribution of cortical bone. These different patterns, probably related to the range of movement at the hip joint and concomitant differences in the load stresses at the femoral neck, are very promising for making locomotor inferences in extinct primates. To evaluate the utility of this feature in the fossil record, we relied on computed tomography applied to the femur of the Late Miocene hominoid Hispanopithecus laietanus as a test-case study. Both an orthograde body plan and orang-like suspensory adaptations had been previously documented for this taxon on different anatomical grounds, leading to the hypothesis that this fossil ape should display a modern ape-like distribution of femoral neck cortical thickness. This is confirmed by the results of this study, leading to the conclusion that Hispanopithecus represents the oldest evidence of a homogeneous cortical bone distribution in the hominoid fossil record. Our results therefore strengthen the utility of femoral neck cortical thickness for making paleobiological inferences on the locomotor repertoire of fossil primates. This feature would be particularly useful for assessing the degree of orthograde arboreal locomotor behaviors vs. terrestrial bipedalism in putative early hominins. Copyright © 2012 Wiley Periodicals, Inc.

  13. Age-Related Effects and Sex Differences in Gray Matter Density, Volume, Mass, and Cortical Thickness from Childhood to Young Adulthood.

    Science.gov (United States)

    Gennatas, Efstathios D; Avants, Brian B; Wolf, Daniel H; Satterthwaite, Theodore D; Ruparel, Kosha; Ciric, Rastko; Hakonarson, Hakon; Gur, Raquel E; Gur, Ruben C

    2017-05-17

    Developmental structural neuroimaging studies in humans have long described decreases in gray matter volume (GMV) and cortical thickness (CT) during adolescence. Gray matter density (GMD), a measure often assumed to be highly related to volume, has not been systematically investigated in development. We used T1 imaging data collected on the Philadelphia Neurodevelopmental Cohort to study age-related effects and sex differences in four regional gray matter measures in 1189 youths ranging in age from 8 to 23 years. Custom T1 segmentation and a novel high-resolution gray matter parcellation were used to extract GMD, GMV, gray matter mass (GMM; defined as GMD × GMV), and CT from 1625 brain regions. Nonlinear models revealed that each modality exhibits unique age-related effects and sex differences. While GMV and CT generally decrease with age, GMD increases and shows the strongest age-related effects, while GMM shows a slight decline overall. Females have lower GMV but higher GMD than males throughout the brain. Our findings suggest that GMD is a prime phenotype for the assessment of brain development and likely cognition and that periadolescent gray matter loss may be less pronounced than previously thought. This work highlights the need for combined quantitative histological MRI studies.SIGNIFICANCE STATEMENT This study demonstrates that different MRI-derived gray matter measures show distinct age and sex effects and should not be considered equivalent but complementary. It is shown for the first time that gray matter density increases from childhood to young adulthood, in contrast with gray matter volume and cortical thickness, and that females, who are known to have lower gray matter volume than males, have higher density throughout the brain. A custom preprocessing pipeline and a novel high-resolution parcellation were created to analyze brain scans of 1189 youths collected as part of the Philadelphia Neurodevelopmental Cohort. A clear understanding of normal

  14. Women with type 2 diabetes mellitus have lower cortical porosity of the proximal femoral shaft using low-resolution CT than nondiabetic women, and increasing glucose is associated with reduced cortical porosity.

    Science.gov (United States)

    Osima, Marit; Kral, Rita; Borgen, Tove T; Høgestøl, Ingvild K; Joakimsen, Ragnar M; Eriksen, Erik F; Bjørnerem, Åshild

    2017-04-01

    Increased cortical porosity has been suggested as a possible factor increasing fracture propensity in patients with type 2 diabetes mellitus (T2DM). This is a paradox because cortical porosity is generally associated with high bone turnover, while bone turnover is reduced in patients with T2DM. We therefore wanted to test the hypothesis that women with T2DM have lower bone turnover markers (BTM) and lower cortical porosity than those without diabetes, and that higher serum glucose and body mass index (BMI) are associated with lower BTM, and with lower cortical porosity. This cross-sectional study is based on a prior nested case-control study including 443 postmenopausal women aged 54-94years from the Tromsø Study, 211 with non-vertebral fracture and 232 fracture-free controls. Of those 443 participants, 22 women exhibited T2DM and 421 women did not have diabetes. All had fasting blood samples assayed for procollagen type I N-terminal propeptide (PINP), C-terminal cross-linking telopeptide of type I collagen (CTX) and glucose, and femoral subtrochanteric architecture was quantified using low-resolution clinical CT and StrAx1.0 software. Women with T2DM had higher serum glucose (7.2 vs. 5.3mmol/L), BMI (29.0 vs. 26.4kg/m2), and higher femoral subtrochanteric total volumetric bone mineral density (vBMD) (783 vs. 715mgHA/cm3), but lower cortical porosity (40.9 vs. 42.8%) than nondiabetic women (all p2 SD lower PINP and CTX, and 0.13 SD lower cortical porosity (all pdiabetes. This indicates that other changes in bone qualities, not increased cortical porosity, are likely to explain the increased fracture propensity in patients with T2DM. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Quantification of Alterations in Cortical Bone Geometry Using Site Specificity Software in Mouse models of Aging and the Responses to Ovariectomy and Altered Loading

    Science.gov (United States)

    Galea, Gabriel L.; Hannuna, Sion; Meakin, Lee B.; Delisser, Peter J.; Lanyon, Lance E.; Price, Joanna S.

    2015-01-01

    Investigations into the effect of (re)modeling stimuli on cortical bone in rodents normally rely on analysis of changes in bone mass and architecture at a narrow cross-sectional site. However, it is well established that the effects of axial loading produce site-specific changes throughout bones’ structure. Non-mechanical influences (e.g., hormones) can be additional to or oppose locally controlled adaptive responses and may have more generalized effects. Tools currently available to study site-specific cortical bone adaptation are limited. Here, we applied novel site specificity software to measure bone mass and architecture at each 1% site along the length of the mouse tibia from standard micro-computed tomography (μCT) images. Resulting measures are directly comparable to those obtained through μCT analysis (R2 > 0.96). Site Specificity analysis was used to compare a number of parameters in tibiae from young adult (19-week-old) versus aged (19-month-old) mice; ovariectomized and entire mice; limbs subjected to short periods of axial loading or disuse induced by sciatic neurectomy. Age was associated with uniformly reduced cortical thickness and site-specific decreases in cortical area most apparent in the proximal tibia. Mechanical loading site-specifically increased cortical area and thickness in the proximal tibia. Disuse uniformly decreased cortical thickness and decreased cortical area in the proximal tibia. Ovariectomy uniformly reduced cortical area without altering cortical thickness. Differences in polar moment of inertia between experimental groups were only observed in the proximal tibia. Aging and ovariectomy also altered eccentricity in the distal tibia. In summary, site specificity analysis provides a valuable tool for measuring changes in cortical bone mass and architecture along the entire length of a bone. Changes in the (re)modeling response determined at a single site may not reflect the response at different locations within the same

  16. Estimation of femoral bone density from trabecular direct wave and cortical guided wave ultrasound velocities measured at the proximal femur in vivo

    DEFF Research Database (Denmark)

    Barkmann, Reinhard; Dencks, Stefanie; Bremer, Alexander

    2008-01-01

    Bone mineral density (BMD) of the proximal femur is a predictor of hip fracture risk. We developed a Quantitative Ultrasound (QUS) scanner for measurements at this site with similar performance (FemUS). In this study we tested if ultrasound velocities of direct waves through trabecular bone and o...

  17. Relationship between trait impulsivity and cortical volume, thickness and surface area in male cocaine users and non-drug using controls

    NARCIS (Netherlands)

    Kaag, A.M.; Crunelle, C.L.; van Wingen, G.A.; Homberg, J.; van den Brink, W.; Reneman, L.

    2014-01-01

    BACKGROUND: Trait impulsivity is commonly associated with cocaine dependence. The few studies that have investigated the relation between trait impulsivity and cortical morphometry, have shown a distinct relation between impulsivity and cortical volume (CV) of temporal, frontal and insula cortex. As

  18. Proximity of maxillary posterior teeth roots to maxillary sinus and adjacent structures using Denta scan?

    OpenAIRE

    Fry, Ramesh Ram; Patidar, Dinesh Chand; Goyal, Samta; Malhotra, Aayush

    2016-01-01

    Aim: The study aimed to investigate the proximity of maxillary posterior teeth roots to maxillary sinus and measure the distance of maxillary posterior teeth roots and the sinus floor as well as the thickness of bone between the roots and alveolar cortical bone using Denta scan?. Materials and Methods: The study samples include Denta scan? images of fifty patients with normally erupted bilateral maxillary first premolar to maxillary second molar. The vertical relationship of each tooth root w...

  19. Hip fractures in the elderly: The role of cortical bone.

    Science.gov (United States)

    Tarantino, Umberto; Rao, Cecilia; Tempesta, Valerio; Gasbarra, Elena; Feola, Maurizio

    2016-10-01

    Osteoporosis is characterised by poor bone quality arising from alterations to trabecular bone. However, recent studies have also described an important role of alterations to cortical bone in the physiopathology of osteoporosis. Although dual-energy X-ray absorptiometry (DXA) is a valid method to assess bone mineral density (BMD), real bone fragility in the presence of comorbidities cannot be evaluated with this method. The aim of this study was to evaluate if cortical thickness could be a good parameter to detect bone fragility in patients with hip fracture, independent of BMD. A retrospective study was conducted on 100 patients with hip fragility fractures. Cortical index was calculated on fractured femur (femoral cortical index [FCI]) and, when possible, on proximal humerus (humeral cortical index [HCI]). All patients underwent densitometric evaluation by DXA. Average value of FCI was 0.43 and of HCI was 0.25. Low values of FCI were found in 21 patients with normal or osteopenic values of BMD, while low values of HCI were found in three patients with non-osteoporotic values of BMD. Cortical thinning measured from X-Ray of the femur identifies 21% additional fracture cases over that identified by a T-score fracture risk even in patients with normal and osteopenic BMD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Correlation analysis of cortical geometry of tibia and humerus of white leghorns using clinical quantitative computed tomography and microcomputed tomography scans.

    Science.gov (United States)

    Regmi, P; Cox, A G; Robison, C I; Karcher, D M

    2017-08-01

    Peripheral quantitative computed tomography (QCT) has been used in poultry bone research in recent years to analyze cortical and cross-sectional geometry. For QCT to be used as a standard research tool for analysis of bones of laying hens (cortical thickness correlate the cortical parameters measured using clinical CT scans with the measurements from micro-CT, the current gold standard. A total of 15 tibiae and 14 humeri of Lohmann White hens was scanned using clinical CT and micro-CT. Reconstruction of the scans generated images with final voxel resolution of 195 μm for clinical CT scans and 46 μm for micro-CT scans. Cortical and total area were measured using MIMICS® software at proximal, middle, and distal locations of 20 mm sections of humerus diaphysis and 30 mm sections of tibia diaphysis. The total area for proximal and middle locations as well as proximal cortical area measurements for humeri produced strong correlation coefficients (R ≥ 0.70). Moderate strength correlation coefficients (R = 0.40 to 0.60) in humeri were seen in middle and distal cortical areas. Distal total area in humeri displayed a weak correlation coefficient (R ≤ 0.3; P = 0.25). Overall, tibiae demonstrated a weaker correlation. Proximal and middle cortical areas indicated moderate correlation coefficients (R = 0.40 to 0.60), while proximal and middle total areas accompanied by distal cortical and total area displayed weak correlation coefficients (R ≤ 0.3). Only the middle cortical area measurement for tibiae was significant (P = 0.03). These results indicate stronger correlation for humeri measurements among the scans than tibia. Overall, cross-sectional area measurements were only low to moderately correlated between clinical and micro-CT scans. © 2017 Poultry Science Association Inc.

  1. A prospective cohort study of digital cushion and corium thickness. Part 1: Associations with body condition, lesion incidence, and proximity to calving.

    Science.gov (United States)

    Newsome, R F; Green, M J; Bell, N J; Bollard, N J; Mason, C S; Whay, H R; Huxley, J N

    2017-06-01

    Claw horn disruption lesions (CHDL) are a major cause of lameness in dairy cattle and are likely a result of excessive forces being applied to the germinal epithelium that produces the claw horn. The digital cushion is a connective tissue structure, containing depots of adipose tissue, that sits beneath the distal phalanx and has been shown to be thicker in fatter cows. Body condition score (BCS) loss is a risk factor for CHDL, and one possible explanation is that fat is mobilized from the digital cushion during negative energy balance, causing the digital cushion to thin and lose force-dissipating capacity, leading to disruption of claw horn growth. This prospective cohort study investigated the association between measures of body fat and sole soft tissue (SST) thickness (a combined measure of the corium and digital cushion beneath the distal phalanx) in a longitudinal manner. The SST of 179 cows in 2 high-yielding dairy herds were measured at 5 assessment points between 8 wk before and 35 wk postcalving. The BCS, back fat thickness (BFT), and lesion incidence were recorded. Data were analyzed in a 4-level mixed effects regression model, with the outcome being SST thickness beneath the flexor tuberosity of the distal phalanx. Data from 827 assessment points were available for analysis. The overall mean of SST was 4.99 mm (standard deviation: 0.95). The SST was thickest 8 wk before calving (5.22 mm, standard deviation: 0.91) and thinnest 1 wk postcalving (4.68 mm, standard deviation: 0.87), suggesting an effect of calving on SST. The BFT was positively correlated with SST in the model with a small effect size (a 10 mm decrease in BFT corresponded with a 0.13 mm decrease in SST), yet the nadir of BFT was 11.0 mm at 9 to 17 wk postcalving (when SST was ∼4.95 mm), rather than occurring with the nadir of SST immediately after calving. The SST also varied with other variables [e.g., cows that developed a sole ulcer or severe sole hemorrhage during the study had

  2. Improved diagnostic accuracy of Alzheimer's disease by combining regional cortical thickness and default mode network functional connectivity: Validated in the Alzheimer's disease neuroimaging initiative set

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ji Eun; Park, Bum Woo; Kim, Sang Joon; Kim, Ho Sung; Choi, Choong Gon; Jung, Seung Jung; Oh, Joo Young; Shim, Woo Hyun [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Lee, Jae Hong; Roh, Jee Hoon [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2017-11-15

    To identify potential imaging biomarkers of Alzheimer's disease by combining brain cortical thickness (CThk) and functional connectivity and to validate this model's diagnostic accuracy in a validation set. Data from 98 subjects was retrospectively reviewed, including a study set (n = 63) and a validation set from the Alzheimer's Disease Neuroimaging Initiative (n = 35). From each subject, data for CThk and functional connectivity of the default mode network was extracted from structural T1-weighted and resting-state functional magnetic resonance imaging. Cortical regions with significant differences between patients and healthy controls in the correlation of CThk and functional connectivity were identified in the study set. The diagnostic accuracy of functional connectivity measures combined with CThk in the identified regions was evaluated against that in the medial temporal lobes using the validation set and application of a support vector machine. Group-wise differences in the correlation of CThk and default mode network functional connectivity were identified in the superior temporal (p < 0.001) and supramarginal gyrus (p = 0.007) of the left cerebral hemisphere. Default mode network functional connectivity combined with the CThk of those two regions were more accurate than that combined with the CThk of both medial temporal lobes (91.7% vs. 75%). Combining functional information with CThk of the superior temporal and supramarginal gyri in the left cerebral hemisphere improves diagnostic accuracy, making it a potential imaging biomarker for Alzheimer's disease.

  3. Proximal Hypospadias

    Science.gov (United States)

    Kraft, Kate H.; Shukla, Aseem R.; Canning, Douglas A.

    2011-01-01

    Hypospadias results from abnormal development of the penis that leaves the urethral meatus proximal to its normal glanular position. Meatal position may be located anywhere along the penile shaft, but more severe forms of hypospadias may have a urethral meatus located at the scrotum or perineum. The spectrum of abnormalities may also include ventral curvature of the penis, a dorsally redundant prepuce, and atrophic corpus spongiosum. Due to the severity of these abnormalities, proximal hypospadias often requires more extensive reconstruction in order to achieve an anatomically and functionally successful result. We review the spectrum of proximal hypospadias etiology, presentation, correction, and possible associated complications. PMID:21516286

  4. Novel ultrasonic bone densitometry based on two longitudinal waves: significant correlation with pQCT measurement values and age-related changes in trabecular bone density, cortical thickness, and elastic modulus of trabecular bone in a normal Japanese population.

    Science.gov (United States)

    Sai, H; Iguchi, G; Tobimatsu, T; Takahashi, K; Otani, T; Horii, K; Mano, I; Nagai, I; Iio, H; Fujita, T; Yoh, K; Baba, H

    2010-10-01

    A reference database for trabecular bone density, cortical thickness, and elastic modulus of trabecular bone for a novel ultrasonic bone densitometry system (LD-100) based on two longitudinal waves (fast and slow) was determined over a wide age range in a normal Japanese population. A novel ultrasonic bone densitometry system (LD-100 system) was applied to create a reference database for trabecular bone density (TBD), cortical thickness (CoTh), and elastic modulus of trabecular bone (EMTb) for this device over a wide age range in a normal Japanese population. In a comparative study between LD-100 and peripheral quantitative computed tomography (pQCT) systems, 52 individuals were examined by both systems at the same radius simultaneously. To create a reference database, a total of 2,380 healthy subjects (1,179 men, 1,201 women), ages 18-99 years, were examined using the LD-100 system. Highly significant correlations between the LD-100 and pQCT systems were found in TBD (r = 0.877, p < 0.001) and CoTh (r = 0.723, p < 0.001). For the reference database, peak values of TBD, CoTh, and EMTb were observed at 30-34 years (255.09 mg/cm(3)), 20-24 years (5.23 mm), and 20-24 years (4.09 GPa) in men, and at 25-29 years (209.24 mg/cm(3)), 25-29 years (3.98 mm), and 20-24 years (3.33 GPa) in women, respectively. The TBD fell significantly (p < 0.05) beginning at 55-59 years in both sexes, with a relatively rapid decrease in women. The CoTh showed a significant decrease beginning at 40-44 years in men and 50-54 years in women. The EMTb showed a significant decrease beginning at 40-44 years in men and 55-59 years in women. The LD-100 system is a useful bone densitometry device and the database of age-related changes in TBD, CoTh, and EMTb established in this study will provide fundamental data for future studies related to bone status.

  5. [Cortical blindness].

    Science.gov (United States)

    Chokron, S

    2014-02-01

    Cortical blindness refers to a visual loss induced by a bilateral occipital lesion. The very strong cooperation between psychophysics, cognitive psychology, neurophysiology and neuropsychology these latter twenty years as well as recent progress in cerebral imagery have led to a better understanding of neurovisual deficits, such as cortical blindness. It thus becomes possible now to propose an earlier diagnosis of cortical blindness as well as new perspectives for rehabilitation in children as well as in adults. On the other hand, studying complex neurovisual deficits, such as cortical blindness is a way to infer normal functioning of the visual system. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  6. Cortical Thickness Changes Associated with Photoparoxysmal Response

    DEFF Research Database (Denmark)

    Hanganu, Alexandru; Groppa, Stanislav A; Deuschl, Günther

    2014-01-01

    Photoparoxysmal response (PPR) is an EEG trait of spike and spike-wave discharges in response to photic stimulation that is closely linked to idiopathic generalized epilepsy (IGE). In our previous studies we showed that PPR is associated with functional alterations in the occipital and frontal...

  7. Swine cortical and cancellous bone: histomorphometric and densitometric characterisation

    Directory of Open Access Journals (Sweden)

    Maria Elena Andreis

    2017-06-01

    Full Text Available Introduction: Swine bone morphology, composition and remodelling are similar to humans’, therefore they are considered good models in bone-related research. They have been used for several studies involving bone growth, bone and cartilage fractures and femoral head osteonecrosis. Nevertheless, the literature about pig normal bone features is incomplete. This work aims to fill the literature gaps on the microarchitecture and Bone Mineral Density (BMD of swine femoral diaphysis and distal epiphysis and tibial plateau and diaphysis. Materials and methods: Five hind limbs were collected from slaughtered 80-100 kg pigs. Microscopic analysis of cortical and cancellous bone from middle/distal femur and proximal/middle tibia was performed to determine basic histomorphometric parameters at different sites. Dual-energy X-Rays Absorptiometry was also employed to evaluate BMD. ANOVA and correlation between BMD, bone area (BA and cortical thickness were performed. Results and discussion: Diaphyseal cortical bone was mostly plexiform both in the tibia and the femur; primary/secondary osteons without clear organization were also found. Mean values for bone area, bone perimeter, trabecular width, number and separation and BMD at different anatomical sites were defined. No significant difference was found for these values at different anatomical sites. BMD proved to be positively correlated with cortical thickness (r=0,80; p<0,01. Despite the small sample size, these results seem homogeneous. They could therefore represent reference values for normal bone parameters in pigs. Applied anatomy and regenerative medicine, in fact, demand very precise information about bone micromorphology, composition and density to provide reliable indication in bone substitutes building. Moreover, since the interpretation of bone abnormalities is based on mastering normal bone characteristics, the definition of reference parameters is mandatory to avoid misinterpretation and

  8. Proximal Femoral Geometry and the Risk of Fractures: Literature Review

    Directory of Open Access Journals (Sweden)

    N.V. Grygorieva

    2016-05-01

    Full Text Available This article presents the literature review of the impact of the upper third of the femur geometry (hip axis length, femoral neck angle, inter-trochanteric length, horizontal offset, thickness of the cortical bone, etc. on the risk of fractures. The article demonstrates the capabilities of techniques for measurement of hip geometry, namely conventional X-ray of pelvic bones, dual-energy X-ray absorptiometry, computed tomography. Possible correlation is shown between some genetic markers and features of the geometry of the upper third of the femur. Also, there are presented the results of own researches of age and sex characteristics of proximal hip geometry parameters in patients without fractures, as well as in patients of older age groups with internal and extraarticular femoral fractures.

  9. Localized cortical thinning in patients with obstructive sleep apnea syndrome.

    Science.gov (United States)

    Joo, Eun Yeon; Jeon, Seun; Kim, Sung Tae; Lee, Jong-Min; Hong, Seung Bong

    2013-08-01

    To investigate differences in cortical thickness in patients with obstructive sleep apnea (OSA) syndrome and healthy controls. Cortical thickness was measured using a three-dimensional surface-based method that enabled more accurate measurement in deep sulci and localized regional mapping. University hospital. Thirty-eight male patients with severe OSA (mean apnea-hypopnea index > 30/h) and 36 age-matched male healthy controls were enrolled. Cortical thickness was obtained at 81,924 vertices across the entire brain by reconstructing inner and outer cortical surfaces using an automated anatomical pipeline. Group difference in cortical thickness and correlation between patients' data and thickness were analyzed by a general linear model. Localized cortical thinning in patients was found in the orbitorectal gyri, dorsolateral/ventromedial prefrontal regions, pericentral gyri, anterior cingulate, insula, inferior parietal lobule, uncus, and basolateral temporal regions at corrected P memory tests compared to healthy controls. Higher number of respiratory arousals was related to cortical thinning of the anterior cingulate and inferior parietal lobule. A significant correlation was observed between the longer apnea maximum duration and the cortical thinning of the dorsolateral prefrontal regions, pericentral gyri, and insula. Retention scores in visual memory tests were associated with cortical thickness of parahippocampal gyrus and uncus. Brain regions with cortical thinning may provide elucidations for prefrontal cognitive dysfunction, upper airway sensorimotor dysregulation, and cardiovascular disturbances in OSA patients, that experience sleep disruption including sleep fragmentation and oxygen desaturation.

  10. Comparing the influence of crestal cortical bone and sinus floor cortical bone in posterior maxilla bi-cortical dental implantation: a three-dimensional finite element analysis.

    Science.gov (United States)

    Yan, Xu; Zhang, Xinwen; Chi, Weichao; Ai, Hongjun; Wu, Lin

    2015-05-01

    This study aimed to compare the influence of alveolar ridge cortical bone and sinus floor cortical bone in sinus areabi-cortical dental implantation by means of 3D finite element analysis. Three-dimensional finite element (FE) models in a posterior maxillary region with sinus membrane and the same height of alveolar ridge of 10 mm were generated according to the anatomical data of the sinus area. They were either with fixed thickness of crestal cortical bone and variable thickness of sinus floor cortical bone or vice versa. Ten models were assumed to be under immediate loading or conventional loading. The standard implant model based on the Nobel Biocare implant system was created via computer-aided design software. All materials were assumed to be isotropic and linearly elastic. An inclined force of 129 N was applied. Von Mises stress mainly concentrated on the surface of crestal cortical bone around the implant neck. For all the models, both the axial and buccolingual resonance frequencies of conventional loading were higher than those of immediate loading; however, the difference is less than 5%. The results showed that bi-cortical implant in sinus area increased the stability of the implant, especially for immediately loading implantation. The thickness of both crestal cortical bone and sinus floor cortical bone influenced implant micromotion and stress distribution; however, crestal cortical bone may be more important than sinus floor cortical bone.

  11. Proximal renal tubular acidosis

    Science.gov (United States)

    Renal tubular acidosis - proximal; Type II RTA; RTA - proximal; Renal tubular acidosis type II ... by alkaline substances, mainly bicarbonate. Proximal renal tubular acidosis (Type II RTA) occurs when bicarbonate is not ...

  12. Proximal 21q deletion as a result of a de novo unbalanced t(12;21) translocation in a patient with dysmorphic features, hepatomegaly, thick myocardium and delayed psychomotor development

    DEFF Research Database (Denmark)

    Jespersgaard, Cathrine; Damgaard, Ida N; Cornelius, Nanna

    2016-01-01

    of the region from 32.3 Mb to 37.1 Mb was more crucial than the deletion of other regions. CASE PRESENTATION: In this study we describe a female patient with dysmorphic features, hepatomegaly, thick myocardium and psychomotor delay. Conventional karyotyping was initially interpreted as full monosomy 21...

  13. The analysis of densitometric and geometric parameters of bilateral proximal phalanges in horses with the use of peripheral quantitative computed tompgraphy

    Directory of Open Access Journals (Sweden)

    Dzierzęcka Małgorzata

    2012-07-01

    Full Text Available Abstract Background Proximal phalanges in horses are among bones that are most prone to injuries. So far, the detailed analysis of densitometric and geometric parameters of both front legs proximal phalanges in horses has not been investigated. The aim of this study was to compare the densitometric and geometric parameters between proximal phalanges in equine both front legs with the use of peripheral quantitative computed tomography (pQCT. Methods The study material comprised isolated both front legs proximal phalanges derived from 22 horses. The structure analysis of the proximal phalanges was conducted with the pQCT. The following bone parameters were determined: bone mineral content, volumetric bone mineral density, total bone area, trabecular area, cortical area, cortical thickness, periosteal circumference, endocortical circumference, Strength Strain Index. Tomographic analysis of proximal phalanges was conducted at three levels: at 15%, 50% and 85% of the bone length. Results The statistical analysis showed that both the densitometric and geometric parameters of the bone at 50% and 85% of its length, did not present any statistically significant differences for the left or right proximal phalanges of the forelimb. At the same time, all examined parameters measured at 15% of the bone length, in the vicinity of the proximal metaphysis revealed significant statistical differences between both front legs proximal phalanges. Conclusions The proximal phalanx parameters in the forelimbs are significantly different for the left and right proximal phalanx at 15% of the length and they indicate higher Strength Strain Index of the left bone in this location. The densitometric and geometric parameters of the bone at 50% and 85% of its length, did not present any statistically significant differences for the left or right proximal phalanges of the left and right forelimbs. The most serious changes caused by asymmetrical load of the thoracic limbs in

  14. Cortical Visual Impairment

    Science.gov (United States)

    ... Frequently Asked Questions Español Condiciones Chinese Conditions Cortical Visual Impairment En Español Read in Chinese What is cortical visual impairment? Cortical visual impairment (CVI) is a decreased ...

  15. Cortical desmoid of the humerus: radiographic and MRI correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kay, Matthew; Counsel, Peter [Princess Margaret Hospital for Children, Department of Diagnostic Imaging, Perth (Australia); Perth Radiological Clinic, Perth (Australia); Wood, David [Princess Margaret Hospital for Children, Department of Orthopedic Surgery, Perth (Australia); Breidahl, William [Perth Radiological Clinic, Perth (Australia)

    2017-07-15

    Cortical desmoids are self-limiting fibro-osseous lesions commonly occurring at the medial supracondylar femur in active adolescents, at either the origin of the medial head of the gastrocnemius or at the insertion of the adductor magnus aponeurosis. Less commonly, in a similar demographic, cortical desmoids may occur in the proximal humerus medially at the insertion of the pectoralis major muscle or laterally at the insertion of the deltoid. The radiographic appearance of the proximal humerus cortical desmoid has been described previously, but not the MRI appearance. We present the radiographic and MRI appearances of a proximal humerus cortical desmoid in a young adolescent who presented for investigation of right shoulder pain. (orig.)

  16. The mechanical benefit of medial support screws in locking plating of proximal humerus fractures.

    Science.gov (United States)

    Zhang, Wen; Zeng, Langqing; Liu, Yanjie; Pan, Yao; Zhang, Wei; Zhang, Changqing; Zeng, Bingfang; Chen, Yunfeng

    2014-01-01

    The purpose of this study was to evaluate the biomechanical advantages of medial support screws (MSSs) in the locking proximal humeral plate for treating proximal humerus fractures. Thirty synthetic left humeri were randomly divided into 3 subgroups to establish two-part surgical neck fracture models of proximal humerus. All fractures were fixed with a locking proximal humerus plate. Group A was fixed with medial cortical support and no MSSs; Group B was fixed with 3 MSSs but without medial cortical support; Group C was fixed with neither medial cortical support nor MSSs. Axial compression, torsional stiffness, shear stiffness, and failure tests were performed. Constructs with medial support from cortical bone showed statistically higher axial and shear stiffness than other subgroups examined (Pproximal humerus was not supported by medial cortical bone, locking plating with medial support screws exhibited higher axial and torsional stiffness than locking plating without medial support screws (P ≤ 0.0207). Specimens with medial cortical bone failed primarily by fracture of the humeral shaft or humeral head. Specimens without medial cortical bone support failed primarily by significant plate bending at the fracture site followed by humeral head collapse or humeral head fracture. Anatomic reduction with medial cortical support was the stiffest construct after a simulated two-part fracture. Significant biomechanical benefits of MSSs in locking plating of proximal humerus fractures were identified. The reconstruction of the medial column support for proximal humerus fractures helps to enhance mechanical stability of the humeral head and prevent implant failure.

  17. Changes in Thickness and Surface Area of the Human Cortex and Their Relationship with Intelligence

    NARCIS (Netherlands)

    Schnack, Hugo G.; Van Haren, Neeltje E M; Brouwer, Rachel M.; Evans, Alan; Durston, Sarah; Boomsma, Dorret I.; Kahn, René S.; Hulshoff Pol, Hilleke E.

    2015-01-01

    Changes in cortical thickness over time have been related to intelligence, but whether changes in cortical surface area are related to general cognitive functioning is unknown. We therefore examined the relationship between intelligence quotient (IQ) and changes in cortical thickness and surface

  18. Cortical visual impairment

    OpenAIRE

    Koželj, Urša

    2013-01-01

    In this thesis we discuss cortical visual impairment, diagnosis that is in the developed world in first place, since 20 percent of children with blindness or low vision are diagnosed with it. The objectives of the thesis are to define cortical visual impairment and the definition of characters suggestive of the cortical visual impairment as well as to search for causes that affect the growing diagnosis of cortical visual impairment. There are a lot of signs of cortical visual impairment. ...

  19. Cortical and trabecular bone at the radius and tibia in male and female adolescents with Down syndrome: a peripheral quantitative computed tomography (pQCT) study.

    Science.gov (United States)

    González-Agüero, A; Vicente-Rodríguez, G; Gómez-Cabello, A; Casajús, J A

    2013-03-01

    We aimed to describe the structure and strength of the tibia and radius of adolescents with Down syndrome. We observed that despite higher levels of volumetric bone mineral density in determined skeletal sites, they are at higher risk of developing osteoporotic fractures in the future due to their lower bone strength indexes. The aims of the study were to describe the cortical and trabecular volumetric bone mineral density (vBMD), bone mineral content (BMC), area, and bone strength in adolescents with Down syndrome (DS) and to compare them with adolescents without disabilities. Thirty adolescents (11 girls) with DS and 28 without disabilities (10 girls) participated in the study. Peripheral quantitative computed tomography measurements were taken at proximal and distal sites of the tibia and radius. Values of total, trabecular, and cortical BMC; vBMD; and area were obtained of each scan. Cortical thickness and endosteal and periosteal circumferences were also measured, and different bone strength indexes were calculated. Student's t tests were applied between groups. The DS group showed greater vBMD at distal radius, BMC at proximal radius, and total and cortical vBMD at proximal tibia. The non-DS group showed higher total and trabecular area at the distal radius and total, cortical, and trabecular BMC and area at distal tibia. Higher values of periosteal and endosteal circumference and bone strength were also found in non-DS group. From these results, it can be believed that even with higher vBMD in determined skeletal sites, adolescents with DS are at higher risk of suffering bone fractures due to an increased fragility by lower resistance to load bending or torsion.

  20. QCT of the proximal femur--which parameters should be measured to discriminate hip fracture?

    Science.gov (United States)

    Museyko, O; Bousson, V; Adams, J; Laredo, J -D; Engelke, K

    2016-03-01

    For quantitative computed tomography (QCT), most relevant variables to discriminate hip fractures were determined. A multivariate analysis showed that trabecular bone mineral density (BMD) of the trochanter with "cortical" thickness of the neck provided better fracture discrimination than total hip integral BMD. A slice-by-slice analysis of the neck or the inclusion of strength-based parameters did not improve fracture discrimination. For QCT of the proximal femur, a large variety of analysis parameters describing bone mineral density, geometry, or strength has been considered. However, in each given study, generally just a small subset was used. The aim of this study was to start with a comprehensive set and then select a best subset of QCT parameters for discrimination of subjects with and without acute osteoporotic hip fractures. The analysis was performed using the population of the European Femur Fracture (EFFECT) study (Bousson et al. J Bone Min Res: Off J Am Soc Bone Min Res 26:881-893, 2011). Fifty-six female control subjects (age 73.2 ± 9.3 years) were compared with 46 female patients (age 80.9 ± 11.1 years) with acute hip fractures. The QCT analysis software MIAF-Femur was used to virtually dissect the proximal femur and analyze more than 1000 parameters, predominantly in the femoral neck. A multivariate best-subset analysis was used to extract the parameters best discriminating hip fractures. All results were adjusted for age, height, and weight differences between the two groups. For the discrimination of all proximal hip fractures as well as for cervical fractures alone, the measurement of neck parameters suffices (area under the curve (AUC) = 0.84). Parameters characterizing bone strength are discriminators of hip fractures; however, in multivariate models, only "cortical" cross-sectional area in the neck center remained as a significant contributor. The combination of one BMD parameter, trabecular BMD of the trochanter, and one geometry

  1. The amount of impaction and loss of reduction in osteoporotic proximal humeral fractures after surgical fixation.

    Science.gov (United States)

    Carbone, S; Papalia, M

    2016-02-01

    After surgical fixation, osteoporotic proximal humeral fractures often show high impaction and loss of reduction. This study aims at assessing the amount of impaction and loss of reduction at a short and medium follow-up. We found an alarming percentage of cases showing these complications in the first postoperative months. This study seeks to quantify the amount of humeral head impaction and loss of reduction in a consecutive series of osteoporotic proximal humerus fractures treated with a locking plate. A series of displaced proximal humerus fractures were prospectively treated with minimally invasive reduction and ostheosynthesis using a locking plate. Diagnosis and classification of fractures were based on X-ray examination and CT scan. Proximal humerus cortical bone thickness (CBTAVG) was studied to assess osteoporosis. Amount of loss of reduction and head fragment impaction were noted at 3 and 18 months of follow-up. Constant score was calculated at 6 and 18 months of follow-up. Thirty-one osteoporotic fractures were studied. Most of the fractures (21, 67.7 %) had a CBTAVG of less than 4 mm. At 3 months of follow-up, 7 cases (22.5 %) had significant loss of reduction and the mean amount of impaction was 2.8 mm. At 18 months of follow-up, only 1 additional fracture showed loss of reduction and mean impaction was 3 mm (p proximal humerus fractures may present an important impaction and loss of reduction in the first 3 months after surgery even if treated with a rigid device and multiple head screws. Surgeons treating these osteoporotic fractures should be aware of these complications even when using a rigid device.

  2. Quantitative ultrasound of cortical bone in the femoral neck predicts femur strength: results of a pilot study.

    Science.gov (United States)

    Grimal, Quentin; Grondin, Julien; Guérard, Sandra; Barkmann, Reinhard; Engelke, Klaus; Glüer, Claus-C; Laugier, Pascal

    2013-02-01

    A significant risk of femoral neck (FN) fracture exists for men and women with an areal bone mineral density (aBMD) higher than the osteoporotic range, as measured with dual-energy X-ray absorptiometry (DXA). Separately measuring the cortical and trabecular FN compartments and combining the results would likely be a critical aspect of enhancing the diagnostic capabilities of a new technique. Because the cortical shell determines a large part of FN strength a novel quantitative ultrasound (QUS) technique that probes the FN cortical compartment was implemented. The sensitivity of the method to variations of FN cortical properties and FN strength was tested. Nine femurs (women, mean age 83 years) were subjected to QUS to measure the through transmission time-of-flight (TOF) at the FN and mechanical tests to assess strength. Quantitative computed tomography (QCT) scans were performed to enable analysis of the dependence of TOF on bone parameters. DXA was also performed for reference. An ultrasound wave propagating circumferentially in the cortical shell was measured in all specimens. Its TOF was not influenced by the properties of the trabecular compartment. Averaged TOF for nine FN measurement positions/orientations was significantly correlated to strength (R2  = 0.79) and FN cortical QCT variables: total BMD (R(2)  = 0.54); regional BMD in the inferoanterior (R2  = 0.90) and superoanterior (R2  = 0.57) quadrants; and moment of inertia (R2  = 0.71). The results of this study demonstrate that QUS can perform a targeted measurement of the FN cortical compartment. Because the method involves mechanical guided waves, the QUS variable is related to the geometric and material properties of the cortical shell (cortical thickness, tissue elasticity, and porosity). This work opens the way to a multimodal QUS assessment of the proximal femur, combining our approach targeting the cortical shell with the existing modality sensitive to the trabecular

  3. Multiset proximity spaces

    Directory of Open Access Journals (Sweden)

    A. Kandil

    2016-10-01

    Full Text Available A multiset is a collection of objects in which repetition of elements is essential. This paper is an attempt to explore the theoretical aspects of multiset by extending the notions of compact, proximity relation and proximal neighborhood to the multiset context. Examples of new multiset topologies, open multiset cover, compact multiset and many identities involving the concept of multiset have been introduced. Further, an integral examples of multiset proximity relations are obtained. A multiset topology induced by a multiset proximity relation on a multiset M has been presented. Also the concept of multiset δ- neighborhood in the multiset proximity space which furnishes an alternative approach to the study of multiset proximity spaces has been mentioned. Finally, some results on this new approach have been obtained and one of the most important results is: every T4- multiset space is semi-compatible with multiset proximity relation δ on M (Theorem 5.10.

  4. Proximal Probes Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Proximal Probes Facility consists of laboratories for microscopy, spectroscopy, and probing of nanostructured materials and their functional properties. At the...

  5. Early adolescent cortical thinning is related to better neuropsychological performance.

    Science.gov (United States)

    Squeglia, Lindsay M; Jacobus, Joanna; Sorg, Scott F; Jernigan, Terry L; Tapert, Susan F

    2013-10-01

    Adolescence is characterized by significant neuromaturation, including extensive cortical thinning, particularly in frontal regions. The goal of this study was to examine the behavioral correlates of neurostructural development in early adolescence. Participants were 185 healthy 12- to 14-year-olds (44% female) recruited from local schools. Participants completed a comprehensive neuropsychological test battery and magnetic resonance imaging session. Cortical surface reconstruction and thickness estimates were performed via FreeSurfer. Age and cortical thickness were negatively correlated in 10 brain regions, 7 of which were in frontal areas (β = −.15 to −.25, ps ≤ .05). Hierarchical linear regressions examined the influence of cortical thickness on working memory, attention, verbal learning and memory, visuospatial functioning, spatial planning and problem solving, and inhibition, controlling for age and intracranial volume. Thinner parietal cortices predicted better performances on tests of verbal learning and memory, visuospatial functioning, and spatial planning and problem solving (β = −.14 to −.24, ps ≤ .05). Age, spanning from 12 to 14 years, accounted for up to 6% of cortical thickness, suggesting substantial thinning during early adolescence, with males showing more accelerated thinning than females between ages 12 and 14. For both males and females, thinner parietal association cortices corresponded with better neurocognitive functioning above and beyond age alone.

  6. The mechanical benefit of medial support screws in locking plating of proximal humerus fractures.

    Directory of Open Access Journals (Sweden)

    Wen Zhang

    Full Text Available BACKGROUND: The purpose of this study was to evaluate the biomechanical advantages of medial support screws (MSSs in the locking proximal humeral plate for treating proximal humerus fractures. METHODS: Thirty synthetic left humeri were randomly divided into 3 subgroups to establish two-part surgical neck fracture models of proximal humerus. All fractures were fixed with a locking proximal humerus plate. Group A was fixed with medial cortical support and no MSSs; Group B was fixed with 3 MSSs but without medial cortical support; Group C was fixed with neither medial cortical support nor MSSs. Axial compression, torsional stiffness, shear stiffness, and failure tests were performed. RESULTS: Constructs with medial support from cortical bone showed statistically higher axial and shear stiffness than other subgroups examined (P<0.0001. When the proximal humerus was not supported by medial cortical bone, locking plating with medial support screws exhibited higher axial and torsional stiffness than locking plating without medial support screws (P ≤ 0.0207. Specimens with medial cortical bone failed primarily by fracture of the humeral shaft or humeral head. Specimens without medial cortical bone support failed primarily by significant plate bending at the fracture site followed by humeral head collapse or humeral head fracture. CONCLUSIONS: Anatomic reduction with medial cortical support was the stiffest construct after a simulated two-part fracture. Significant biomechanical benefits of MSSs in locking plating of proximal humerus fractures were identified. The reconstruction of the medial column support for proximal humerus fractures helps to enhance mechanical stability of the humeral head and prevent implant failure.

  7. Age-related temporal and parietal cortical thinning in autism spectrum disorders

    OpenAIRE

    Wallace, Gregory L.; Dankner, Nathan; Kenworthy, Lauren; Giedd, Jay N.; Martin, Alex

    2010-01-01

    Studies of head size and brain volume in autism spectrum disorders have suggested that early cortical overgrowth may be followed by prematurely arrested growth. However, the few investigations quantifying cortical thickness have yielded inconsistent results, probably due to variable ages and/or small sample sizes. We assessed differences in cortical thickness between high-functioning adolescent and young adult males with autism spectrum disorders (n = 41) and matched typically developing male...

  8. Accelerated growth plate mineralization and foreshortened proximal limb bones in fetuin-A knockout mice.

    Directory of Open Access Journals (Sweden)

    Jong Seto

    Full Text Available The plasma protein fetuin-A/alpha2-HS-glycoprotein (genetic symbol Ahsg is a systemic inhibitor of extraskeletal mineralization, which is best underscored by the excessive mineral deposition found in various tissues of fetuin-A deficient mice on the calcification-prone genetic background DBA/2. Fetuin-A is known to accumulate in the bone matrix thus an effect of fetuin-A on skeletal mineralization is expected. We examined the bones of fetuin-A deficient mice maintained on a C57BL/6 genetic background to avoid bone disease secondary to renal calcification. Here, we show that fetuin-A deficient mice display normal trabecular bone mass in the spine, but increased cortical thickness in the femur. Bone material properties, as well as mineral and collagen characteristics of cortical bone were unaffected by the absence of fetuin-A. In contrast, the long bones especially proximal limb bones were severely stunted in fetuin-A deficient mice compared to wildtype littermates, resulting in increased biomechanical stability of fetuin-A deficient femora in three-point-bending tests. Elevated backscattered electron signal intensities reflected an increased mineral content in the growth plates of fetuin-A deficient long bones, corroborating its physiological role as an inhibitor of excessive mineralization in the growth plate cartilage matrix--a site of vigorous physiological mineralization. We show that in the case of fetuin-A deficiency, active mineralization inhibition is a necessity for proper long bone growth.

  9. Accelerated Growth Plate Mineralization and Foreshortened Proximal Limb Bones in Fetuin-A Knockout Mice

    Science.gov (United States)

    Gupta, Himadri S.; Schäfer, Cora; Krauss, Stefanie; Dunlop, John W. C.; Masic, Admir; Kerschnitzki, Michael; Zaslansky, Paul; Boesecke, Peter; Catalá-Lehnen, Philip; Schinke, Thorsten; Fratzl, Peter; Jahnen-Dechent, Willi

    2012-01-01

    The plasma protein fetuin-A/alpha2-HS-glycoprotein (genetic symbol Ahsg) is a systemic inhibitor of extraskeletal mineralization, which is best underscored by the excessive mineral deposition found in various tissues of fetuin-A deficient mice on the calcification-prone genetic background DBA/2. Fetuin-A is known to accumulate in the bone matrix thus an effect of fetuin-A on skeletal mineralization is expected. We examined the bones of fetuin-A deficient mice maintained on a C57BL/6 genetic background to avoid bone disease secondary to renal calcification. Here, we show that fetuin-A deficient mice display normal trabecular bone mass in the spine, but increased cortical thickness in the femur. Bone material properties, as well as mineral and collagen characteristics of cortical bone were unaffected by the absence of fetuin-A. In contrast, the long bones especially proximal limb bones were severely stunted in fetuin-A deficient mice compared to wildtype littermates, resulting in increased biomechanical stability of fetuin-A deficient femora in three-point-bending tests. Elevated backscattered electron signal intensities reflected an increased mineral content in the growth plates of fetuin-A deficient long bones, corroborating its physiological role as an inhibitor of excessive mineralization in the growth plate cartilage matrix - a site of vigorous physiological mineralization. We show that in the case of fetuin-A deficiency, active mineralization inhibition is a necessity for proper long bone growth. PMID:23091616

  10. Representational Thickness

    DEFF Research Database (Denmark)

    Mullins, Michael

    to improve design conditions for architects, thereby increasing the “thickness of representation”. The study commences from a broader theoretical enquiry, a review of previous research and examples of relevant context in which virtual reality has been used in practice. It develops from this discussion three......Contemporary communicational and informational processes contribute to the shaping of our physical environment by having a powerful influence on the process of design. Applications of virtual reality (VR) are transforming the way architecture is conceived and produced by introducing dynamic...... elements into the process of design. Through its immersive properties, virtual reality allows access to a spatial experience of a computer model very different to both screen based simulations as well as traditional forms of architectural representation. The dissertation focuses on processes of the current...

  11. Humeral head circle-fit method greatly increases reliability and accuracy when measuring anterior-posterior radiographs of the proximal humerus.

    Science.gov (United States)

    Mears, Chad S; Langston, Tanner D; Phippen, Colton M; Burkhead, Wayne Z; Skedros, John G

    2017-10-01

    Measurements made on routine A-P radiographs can predict strength/quality of the proximal humerus, as shown in terms of two easy-to-measure parameters: Cortical index (CI) and mean-combined cortical thickness (MCCT). Because of high variability inherent when using established methods to measure these parameters, we describe a new orientation system. Using digitized radiographs of 33 adult proximal humeri, five observers measured anatomical reference locations in accordance with: (i) Tingart et al. (2003) method, (ii) Mather et al. (2013) method, and (iii) our new humeral head Circle-Fit method (CFM). The Tingart and Mather methods measure CI and MCCT with respect to upper and lower edges of 20 mm tall rectangles fit to a proximal diaphyseal location where endosteal (Tingart) or periosteal (Mather) cortical margins become parallel. But high intra- and inter-observer variability occurs when placing the rectangles because of uncertainty in identifying cortical parallelism. With the CFM an adjustable circle is fit to the humeral head articular surface, which reliably and easily establishes a proximal metaphyseal landmark (M1) at the surgical neck. Distal locations are then designated at successive 10 mm increments below M1, including a second metaphyseal landmark (M2) followed by diaphyseal (D) locations (D1, D2 ⋯D6). D1 corresponds most closely to the proximal edges of the rectangles used in the other methods. Results showed minimal inter-observer variations (mean error, 1.5 ± 1.1 mm) when the CFM is used to establish diaphyseal locations for making CI and MCCT measurements when compared to each of the other methods (mean error range, 10.7 ± 5.9 to 13.3 ± 6.7 mm) (p < 0.001). © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2313-2322, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  12. Cortical correlates of affective syndrome in dementia due to Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Thaís T. Hayata

    2015-07-01

    Full Text Available Neuropsychiatric symptoms in Alzheimer’s disease (AD are prevalent, however their relationship with patterns of cortical atrophy is not fully known. Objectives To compare cortical atrophy’s patterns between AD patients and healthy controls; to verify correlations between neuropsychiatric syndromes and cortical atrophy. Method 33 AD patients were examined by Neuropsychiatric Inventory (NPI. Patients and 29 controls underwent a 3T MRI scanning. We considered four NPI syndromes: affective, apathy, hyperactivity and psychosis. Correlations between structural imaging and neuropsychiatric scores were performed by Freesurfer. Results were significant with a p-value < 0.05, corrected for multiple comparisons. Results Patients exhibited atrophy in entorhinal cortices, left inferior and middle temporal gyri, and precuneus bilaterally. There was correlation between affective syndrome and cortical thickness in right frontal structures, insula and temporal pole. Conclusion Cortical thickness measures revealed atrophy in mild AD. Depression and anxiety symptoms were associated with atrophy of right frontal, temporal and insular cortices.

  13. Site-specific advantages in skeletal geometry and strength at the proximal femur and forearm in young female gymnasts.

    Science.gov (United States)

    Dowthwaite, Jodi N; Rosenbaum, Paula F; Scerpella, Tamara A

    2012-05-01

    We evaluated site-specific skeletal adaptation to loading during growth, comparing radius (RAD) and femoral neck (FN) DXA scans in young female gymnasts (GYM) and non-gymnasts (NON). Subjects from an ongoing longitudinal study (8-26yr old) underwent annual DXA scans (proximal femur, forearm, total body) and anthropometry, completing maturity and physical activity questionnaires. This cross-sectional analysis used the most recent data meeting the following criteria: gynecological age ≤2.5yr post-menarche; and GYM annual mean gymnastic exposure ≥5.0h/wk in the prior year. Bone geometric and strength indices were derived from scans for 173 subjects (8-17yr old) via hip structural analysis (femoral narrow neck, NN) and similar radius formulae (1/3 and Ultradistal (UD)). Maturity was coded as M1 (Tanner I breast), M2 (pre-menarche, ≥Tanner II breast) or M3 (post-menarche). ANOVA and chi square compared descriptive data. Two factor ANCOVA adjusted for age, height, total body non-bone lean mass and percent body fat; significance was tested for main effects and interactions between gymnastic exposure and maturity. At the distal radius, GYM means were significantly greater than NON means for all variables (padvantages only in M1 and M3; for BMC and buckling ratio, M1 advantages were greatest); 2) 1/3 radius BMC, width, endosteal diameter, cortical cross-sectional area, and section modulus (GYM advantages primarily post-menarche); and 3) UD radius BMC and axial compressive strength (GYM advantages were larger with greater maturity, greatest post-menarche). Maturity-specific comparisons suggested site-specific skeletal adaptation to loading during growth, with greater advantages at the radius versus the proximal femur. At the radius, GYM advantages included greater bone width, cortical cross-sectional area and cortical thickness; in contrast, at the femoral neck, GYM bone tissue cross-sectional area and cortical thickness were greater, but bone width was narrower than

  14. Cortical maturation and myelination in healthy toddlers and young children.

    Science.gov (United States)

    Deoni, Sean C L; Dean, Douglas C; Remer, Justin; Dirks, Holly; O'Muircheartaigh, Jonathan

    2015-07-15

    The maturation of cortical structures, and the establishment of their connectivity, are critical neurodevelopmental processes that support and enable cognitive and behavioral functioning. Measures of cortical development, including thickness, curvature, and gyrification have been extensively studied in older children, adolescents, and adults, revealing regional associations with cognitive performance, and alterations with disease or pathology. In addition to these gross morphometric measures, increased attention has recently focused on quantifying more specific indices of cortical structure, in particular intracortical myelination, and their relationship to cognitive skills, including IQ, executive functioning, and language performance. Here we analyze the progression of cortical myelination across early childhood, from 1 to 6 years of age, in vivo for the first time. Using two quantitative imaging techniques, namely T1 relaxation time and myelin water fraction (MWF) imaging, we characterize myelination throughout the cortex, examine developmental trends, and investigate hemispheric and gender-based differences. We present a pattern of cortical myelination that broadly mirrors established histological timelines, with somatosensory, motor and visual cortices myelinating by 1 year of age; and frontal and temporal cortices exhibiting more protracted myelination. Developmental trajectories, defined by logarithmic functions (increasing for MWF, decreasing for T1), were characterized for each of 68 cortical regions. Comparisons of trajectories between hemispheres and gender revealed no significant differences. Results illustrate the ability to quantitatively map cortical myelination throughout early neurodevelopment, and may provide an important new tool for investigating typical and atypical development. Copyright © 2015. Published by Elsevier Inc.

  15. Spontaneously emerging cortical representations of visual attributes

    Science.gov (United States)

    Kenet, Tal; Bibitchkov, Dmitri; Tsodyks, Misha; Grinvald, Amiram; Arieli, Amos

    2003-10-01

    Spontaneous cortical activity-ongoing activity in the absence of intentional sensory input-has been studied extensively, using methods ranging from EEG (electroencephalography), through voltage sensitive dye imaging, down to recordings from single neurons. Ongoing cortical activity has been shown to play a critical role in development, and must also be essential for processing sensory perception, because it modulates stimulus-evoked activity, and is correlated with behaviour. Yet its role in the processing of external information and its relationship to internal representations of sensory attributes remains unknown. Using voltage sensitive dye imaging, we previously established a close link between ongoing activity in the visual cortex of anaesthetized cats and the spontaneous firing of a single neuron. Here we report that such activity encompasses a set of dynamically switching cortical states, many of which correspond closely to orientation maps. When such an orientation state emerged spontaneously, it spanned several hypercolumns and was often followed by a state corresponding to a proximal orientation. We suggest that dynamically switching cortical states could represent the brain's internal context, and therefore reflect or influence memory, perception and behaviour.

  16. Capacitive proximity sensor

    Science.gov (United States)

    Kronberg, James W.

    1994-01-01

    A proximity sensor based on a closed field circuit. The circuit comprises a ring oscillator using a symmetrical array of plates that creates an oscillating displacement current. The displacement current varies as a function of the proximity of objects to the plate array. Preferably the plates are in the form of a group of three pair of symmetric plates having a common center, arranged in a hexagonal pattern with opposing plates linked as a pair. The sensor produces logic level pulses suitable for interfacing with a computer or process controller. The proximity sensor can be incorporated into a load cell, a differential pressure gauge, or a device for measuring the consistency of a characteristic of a material where a variation in the consistency causes the dielectric constant of the material to change.

  17. Neighborhoods and manageable proximity

    Directory of Open Access Journals (Sweden)

    Stavros Stavrides

    2011-08-01

    Full Text Available The theatricality of urban encounters is above all a theatricality of distances which allow for the encounter. The absolute “strangeness” of the crowd (Simmel 1997: 74 expressed, in its purest form, in the absolute proximity of a crowded subway train, does not generally allow for any movements of approach, but only for nervous hostile reactions and submissive hypnotic gestures. Neither forced intersections in the course of pedestrians or vehicles, nor the instantaneous crossing of distances by the technology of live broadcasting and remote control give birth to places of encounter. In the forced proximity of the metropolitan crowd which haunted the city of the 19th and 20th century, as well as in the forced proximity of the tele-presence which haunts the dystopic prospect of the future “omnipolis” (Virilio 1997: 74, the necessary distance, which is the stage of an encounter between different instances of otherness, is dissipated.

  18. Cortical thickness as a contributor to abnormal oscillations in schizophrenia?

    Directory of Open Access Journals (Sweden)

    J. Christopher Edgar

    2014-01-01

    Discussion: Left STG low-frequency and steady-state gamma abnormalities distinguish SZ and HC. Disease-associated damage to STG gray matter in schizophrenia may disrupt the age-related left STG gamma-band function–structure relationships observed in controls.

  19. Sexual Orientation Related Differences in Cortical Thickness in Male Individuals

    OpenAIRE

    Abé, Christoph; Johansson, Emilia; Allzén, Elin; Savic, Ivanka

    2014-01-01

    Previous neuroimaging studies demonstrated sex and also sexual orientation related structural and functional differences in the human brain. Genetic information and effects of sex hormones are assumed to contribute to the male/female differentiation of the brain, and similar effects could play a role in processes influencing human's sexual orientation. However, questions about the origin and development of a person's sexual orientation remain unanswered, and research on sexual orientation rel...

  20. Retrosplenial cortical thinning as a possible major contributor for cognitive impairment in HIV patients

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Na-Young [The Catholic University of Korea, Department of Radiology, College of Medicine, Seoul (Korea, Republic of); Hong, Jinwoo; Yoon, Uicheul [Catholic University of Daegu, Department of Biomedical Engineering, College of Health and Medical Science, Gyeongsan-si, Gyeongbuk (Korea, Republic of); Choi, Jun Yong [Yonsei University College of Medicine, Department of Internal Medicine and AIDS Research Institute, Seoul (Korea, Republic of); Lee, Seung-Koo [Yonsei University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Lim, Soo Mee [Ewha Womans University, School of Medicine, Department of Radiology, Seoul (Korea, Republic of)

    2017-11-15

    To identify brain cortical regions relevant to HIV-associated neurocognitive disorder (HAND) in HIV patients. HIV patients with HAND (n = 10), those with intact cognition (HIV-IC; n = 12), and age-matched, seronegative controls (n = 11) were recruited. All participants were male and underwent 3-dimensional T1-weighted imaging. Both vertex-wise and region of interest (ROI) analyses were performed to analyse cortical thickness. Compared to controls, both HIV-IC and HAND showed decreased cortical thickness mainly in the bilateral primary sensorimotor areas, extending to the prefrontal and parietal cortices. When directly comparing HIV-IC and HAND, HAND showed cortical thinning in the left retrosplenial cortex, left dorsolateral prefrontal cortex, left inferior parietal lobule, bilateral superior medial prefrontal cortices, right temporoparietal junction and left hippocampus, and cortical thickening in the left middle occipital cortex. Left retrosplenial cortical thinning showed significant correlation with slower information processing, declined verbal memory and executive function, and impaired fine motor skills. This study supports previous research suggesting the selective vulnerability of the primary sensorimotor cortices and associations between cortical thinning in the prefrontal and parietal cortices and cognitive impairment in HIV-infected patients. Furthermore, for the first time, we propose retrosplenial cortical thinning as a possible major contributor to HIV-associated cognitive impairment. (orig.)

  1. Effects of endurance exercises on microarchitecture of proximal tibia in ovariectomized rats

    Directory of Open Access Journals (Sweden)

    Valiollah Dabidy Roshan

    2012-01-01

    Full Text Available Background: Appropriate endurance exercise can change bone mass density and strength of weight-bearing bones in both animals and humans, but its effects on the microstructure are not known. This study aimed to determine skeletal changes induced by the treadmill running endurance in ovariectomized adult mice.Methods: twenty-seven adult female rats were divided into experimental and control groups.(Each group consisted of 9 rats and 9 rats were killed to determine baseline values. Experimental group performed the progressive running exercise for 8 weeks, 12 to 20 m/min, 10 to 59 min, 5 times per week. Microarchitecture of dense and spongy bone tissues in the proximal tibia epiphysis were measured by using a semi-automated image analysis system. Data was analyzed using t-student tests (P<0.05.Results: Running on treadmill causes a significant increase in the thickness and volume of spongy tissue and bone tissue was dense and spongy epiphysis upper tibia (P<0.05. Compared to control, treadmill running group showed significant difference in trabecular thickness and separation. Conclusion: Ovariectomy may decrease the microarchitecture properties of cortical tissue and especially, trabecular tissue in weight-bearing bones. Increasing bone strength induced by endurance exercise is mediated by changes in bon microarchitecture.

  2. Effect of porosity, tissue density, and mechanical properties on radial sound speed in human cortical bone

    Energy Technology Data Exchange (ETDEWEB)

    Eneh, C. T. M., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi; Töyräs, J., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi; Jurvelin, J. S., E-mail: jukka.jurvelin@uef.fi [Department of Applied Physics, University of Eastern Finland, P.O. Box 1627, Kuopio FI-70211, Finland and Diagnostic Imaging Center, Kuopio University Hospital, P.O. Box 100, Kuopio FI-70029 (Finland); Malo, M. K. H., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi; Liukkonen, J., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi [Department of Applied Physics, University of Eastern Finland, P.O. Box 1627, Kuopio FI-70211 (Finland); Karjalainen, J. P., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi [Bone Index Finland Ltd., P.O. Box 1188, Kuopio FI-70211 (Finland)

    2016-05-15

    Purpose: The purpose of this study was to investigate the effect of simultaneous changes in cortical porosity, tissue mineral density, and elastic properties on radial speed of sound (SOS) in cortical bone. The authors applied quantitative pulse-echo (PE) ultrasound techniques that hold much potential especially for screening of osteoporosis at primary healthcare facilities. Currently, most PE measurements of cortical thickness, a well-known indicator of fracture risk, use a predefined estimate for SOS in bone to calculate thickness. Due to variation of cortical bone porosity, the use of a constant SOS value propagates to an unknown error in cortical thickness assessment by PE ultrasound. Methods: The authors conducted 2.25 and 5.00 MHz focused PE ultrasound time of flight measurements on femoral diaphyses of 18 cadavers in vitro. Cortical porosities of the samples were determined using microcomputed tomography and related to SOS in the samples. Additionally, the effect of cortical bone porosity and mechanical properties of the calcified matrix on SOS was investigated using numerical finite difference time domain simulations. Results: Both experimental measurements and simulations demonstrated significant negative correlation between radial SOS and cortical porosity (R{sup 2} ≥ 0.493, p < 0.01 and R{sup 2} ≥ 0.989, p < 0.01, respectively). When a constant SOS was assumed for cortical bone, the error due to variation of cortical bone porosity (4.9%–16.4%) was about 6% in the cortical thickness assessment in vitro. Conclusions: Use of a predefined, constant value for radial SOS in cortical bone, i.e., neglecting the effect of measured variation in cortical porosity, propagated to an error of 6% in cortical thickness. This error can be critical as characteristic cortical thinning of 1.10% ± 1.06% per yr decreases bending strength of the distal radius and results in increased fragility in postmenopausal women. Provided that the cortical porosity can be estimated

  3. Cortical Lewy Body Dementia

    Directory of Open Access Journals (Sweden)

    W. R. G. Gibb

    1990-01-01

    Full Text Available In cortical Lewy body dementia the distribution of Lewy bodies in the nervous system follows that of Parkinson's disease, except for their greater profusion in the cerebral cortex. The cortical tangles and plaques of Alzheimer pathology are often present, the likely explanation being that Alzheimer pathology provokes dementia in many patients. Pure cortical Lewy body dementia without Alzheimer pathology is uncommon. The age of onset reflects that of Parkinson's disease, and clinical features, though not diagnostic, include aphasias, apraxias, agnosias, paranoid delusions and visual hallucinations. Parkinsonism may present before or after the dementia, and survival duration is approximately half that seen in Parkinson's disease without dementia.

  4. Atrofia muscular proximal familiar

    Directory of Open Access Journals (Sweden)

    José Antonio Levy

    1962-09-01

    Full Text Available Os autores relatam dois casos de atrofia muscular proximal familiar, moléstia caracterizada por déficit motor e atrofias musculares de distribuição proximal, secundárias a lesão de neurônios periféricos. Assim, como em outros casos descritos na literatura, foi feito inicialmente o diagnóstico de distrofia muscular progressiva. O diagnóstico correto foi conseguido com auxílio da eletromiografia e da biopsia muscular.

  5. Lhx2 regulates the timing of β-catenin-dependent cortical neurogenesis.

    Science.gov (United States)

    Hsu, Lea Chia-Ling; Nam, Sean; Cui, Yi; Chang, Ching-Pu; Wang, Chia-Fang; Kuo, Hung-Chih; Touboul, Jonathan D; Chou, Shen-Ju

    2015-09-29

    The timing of cortical neurogenesis has a major effect on the size and organization of the mature cortex. The deletion of the LIM-homeodomain transcription factor Lhx2 in cortical progenitors by Nestin-cre leads to a dramatically smaller cortex. Here we report that Lhx2 regulates the cortex size by maintaining the cortical progenitor proliferation and delaying the initiation of neurogenesis. The loss of Lhx2 in cortical progenitors results in precocious radial glia differentiation and a temporal shift of cortical neurogenesis. We further investigated the underlying mechanisms at play and demonstrated that in the absence of Lhx2, the Wnt/β-catenin pathway failed to maintain progenitor proliferation. We developed and applied a mathematical model that reveals how precocious neurogenesis affected cortical surface and thickness. Thus, we concluded that Lhx2 is required for β-catenin function in maintaining cortical progenitor proliferation and controls the timing of cortical neurogenesis.

  6. [Experimental proximal carpectomy. Biodynamics].

    Science.gov (United States)

    Kuhlmann, J N

    1992-01-01

    Proximal carpectomy was performed in 10 fresh cadavre wrists. Dynamic x-rays were taken and the forces necessary to obtain different movements before and after the operation were measured. Comparison of these parameters clearly defines the advantages and limitations of carpectomy and indicates the reasons.

  7. Proximate Analysis of Coal

    Science.gov (United States)

    Donahue, Craig J.; Rais, Elizabeth A.

    2009-01-01

    This lab experiment illustrates the use of thermogravimetric analysis (TGA) to perform proximate analysis on a series of coal samples of different rank. Peat and coke are also examined. A total of four exercises are described. These are dry exercises as students interpret previously recorded scans. The weight percent moisture, volatile matter,…

  8. Proximal Tibial Bone Graft

    Science.gov (United States)

    ... the Big Toe Ailments of the Smaller Toes Diabetic Foot Treatments Currently selected Injections and other Procedures Treatments ... from which the bone was taken if the foot/ankle surgeries done at the same time allow for it. ... problems after a PTBG include infection, fracture of the proximal tibia and pain related ...

  9. Atrofia cortical posterior

    OpenAIRE

    Delgado D,Carolina; Donoso S,Archibaldo

    2009-01-01

    Posterior cortical atrophy (PCA) is a neurodegenerative syndrome, usually due to Alzheimer's disease. The first symptoms are progressive impairment of visuo spatial (Balint's and Gertsmann's syndromes) or visuo perceptive (visual agnosia, alexia) function. Episodic memory and executive function are spared until later stages. We report two males aged 51 and 55years and three females aged 50, 54 and 56 years, with posterior cortical atrophy. Ophthalmologic study was normal in all. Presenting si...

  10. Turbine airfoil with outer wall thickness indicators

    Science.gov (United States)

    Marra, John J; James, Allister W; Merrill, Gary B

    2013-08-06

    A turbine airfoil usable in a turbine engine and including a depth indicator for determining outer wall blade thickness. The airfoil may include an outer wall having a plurality of grooves in the outer surface of the outer wall. The grooves may have a depth that represents a desired outer surface and wall thickness of the outer wall. The material forming an outer surface of the outer wall may be removed to be flush with an innermost point in each groove, thereby reducing the wall thickness and increasing efficiency. The plurality of grooves may be positioned in a radially outer region of the airfoil proximate to the tip.

  11. Proximal femoral fractures

    DEFF Research Database (Denmark)

    Palm, Henrik; Teixidor, Jordi

    2015-01-01

    -displaced femoral neck fractures and prosthesis for displaced among the elderly; and sliding hip screw for stabile- and intramedullary nails for unstable- and sub-trochanteric fractures) but they are based on a variety of criteria and definitions - and often leave wide space for the individual surgeons' subjective...... guidelines for hip fracture surgery and discuss a method for future pathway/guideline implementation and evaluation. METHODS: By a PubMed search in March 2015 six studies of surgical treatment pathways covering all types of proximal femoral fractures with publication after 1995 were identified. Also we...... searched the homepages of the national heath authorities and national orthopedic societies in West Europe and found 11 national or regional (in case of no national) guidelines including any type of proximal femoral fracture surgery. RESULTS: Pathway consensus is outspread (internal fixation for un...

  12. Proximal humeral fractures

    OpenAIRE

    Mauro, Craig S.

    2011-01-01

    Proximal humeral fractures may present with many different configurations in patients with varying co-morbities and expectations. As a result, the treating physician must understand the fracture pattern, the quality of the bone, other patient-related factors, and the expanding range of reconstructive options to achieve the best functional outcome and to minimize complications. Current treatment options range from non-operative treatment with physical therapy to fracture fixation using percuta...

  13. Patterns of cortical thinning in nondemented Parkinson's disease patients.

    Science.gov (United States)

    Uribe, Carme; Segura, Barbara; Baggio, Hugo Cesar; Abos, Alexandra; Marti, Maria Jose; Valldeoriola, Francesc; Compta, Yaroslau; Bargallo, Nuria; Junque, Carme

    2016-05-01

    Clinical variability in the Parkinson's disease phenotype suggests the existence of disease subtypes. We investigated whether distinct anatomical patterns of atrophy can be identified in Parkinson's disease using a hypothesis-free, data-driven approach based on cortical thickness data. T1-weighted 3-tesla MRI and a comprehensive neuropsychological assessment were performed in a sample of 88 nondemented Parkinson's disease patients and 31 healthy controls. We performed a hierarchical cluster analysis of imaging data using Ward's linkage method. A general linear model with cortical thickness data was used to compare clustering groups. We observed 3 patterns of cortical thinning in patients when compared with healthy controls. Pattern 1 (n = 30, 34.09%) consisted of cortical atrophy in bilateral precentral gyrus, inferior and superior parietal lobules, cuneus, posterior cingulate, and parahippocampal gyrus. These patients showed worse cognitive performance when compared with controls and the other 2 patterns. Pattern 2 (n = 29, 32.95%) consisted of cortical atrophy involving occipital and frontal as well as superior parietal areas and included patients with younger age at onset. Finally, in pattern 3 (n = 29, 32.95%), there was no detectable cortical thinning. Patients in the 3 patterns did not differ in disease duration, motor severity, dopaminergic medication doses, or presence of mild cognitive impairment. Three cortical atrophy subtypes were identified in nondemented Parkinson's disease patients: (1) parieto-temporal pattern of atrophy with worse cognitive performance, (2) occipital and frontal cortical atrophy and younger disease onset, and (3) patients without detectable cortical atrophy. These findings may help identify prognosis markers in Parkinson's disease. © 2016 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society. © 2016 The Authors. Movement Disorders

  14. Simple radiographic assessment of bone quality is associated with loss of surgical fixation in patients with proximal humeral fractures.

    Science.gov (United States)

    Newton, Ashley W; Selvaratnam, Veenesh; Pydah, Satya K; Nixon, Matthew F

    2016-04-01

    This study aimed to determine if the ratio of cortical thickness to shaft diameter of the humerus, as measured on a simple anterior-posterior shoulder radiograph, is associated with surgical fixation failure. 64 consecutive fractures in 63 patients (mean age 66.1 years, range 35-90) operated with surgical fixation between March 2011 and July 2014 using PERI-LOC locking plate and screws (Smith and Nephew, UK) were identified. Predictors of bone quality were measured from preoperative radiographs, including ratio of the medial cortex to shaft diameter (medial cortical ratio, MCR). Loss of fixation (displacement, screw cut out, or change in neck-shaft angle >4 degrees) was determined on follow-up radiographs. Loss of fixation occurred in 14 patients (21.9%) during the follow up. Patients were older in the failure group 72.8 vs. 64.2 years (p=0.007). The MCR was significantly lower in patients with failed fixation 0.170 vs 0.202, p=0.019. Loss of fixation is three times more likely in patients with a MCR fracture parts led to increased failure rate (p=0.0005). Medial cortex ratio is significantly associated with loss of surgical fixation and may prove to be a useful adjunct for clinical decision making in patients with proximal humeral fractures. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Tunable Magnetic Proximity Effects in Graphene Junctions

    Science.gov (United States)

    Lazic, Predrag; Belashchenko, Kirill; Zutic, Igor

    2015-03-01

    The characteristic length of the magnetic proximity effects exceed the thickness of a graphene layer leading to an important, but typically overlooked, modifications of equilibrium and transport properties, as well as the implications for graphene spintronics. Using the first-principles studies that integrate a real space density functional theory (GPAW) with the state-of-the art boundary elements electrostatic code based on the Robin Hood method, we explore tunable electronic structure and magnetic proximity effects in the ferromagnet/insulator/graphene junctions. We show that the inclusion of a finite-size gate electrodes and van der Walls interaction lead to nontrivial effects that could also be important in other two-dimensional materials beyond graphene. Work supported by US ONR, NSF-DMR and Nebraska NSF MRSEC.

  16. Focal Cortical and Subcortical Atrophy in Early Parkinson’s Disease

    OpenAIRE

    Tinaz, Sule; Courtney, Maureen G.; Stern, Chantal E.; Phil, D.

    2010-01-01

    Neurodegeneration in clinically manifest Parkinson’s disease affects the substantia nigra pars compacta, and gradually spreads to the limbic cortices and the neocortex. We used MRI imaging coupled with automated surface reconstruction and segmentation methods to examine cortical thickness and subcortical volumes in nondemented, early-stage Parkinson’s disease patients compared to matched healthy control participants. These methods, which have been previously used to document cortical thicknes...

  17. [Cortical control in locomotion].

    Science.gov (United States)

    Mori, Futoshi; Nakajima, Katsumi

    2010-11-01

    Although simple in appearance, bipedal (Bp) and even quadrupedal (Qp) locomotion are highly tuned motor behaviors that require coordinated control in the spatial and temporal domains of head, neck, trunk, and limbs. Seamless integration of limb movements and accompanying posture is a crucial determinant for the execution of desired locomotor movements. Recent functional brain imaging studies have shown that multiple cerebral sensorimotor cortices and the cerebellum are highly activated during human BP locomotion, suggesting that humans depend on the cerebrum and cerebellum for the elaboration of Bp locomotion. We have found that a young Japanese monkey, Macaca fuscata, acquires novel Bp walking capability with a long-term locomotor task and physical maturation. This model animal has kinematic features that are common with those of humans. Our imaging study showed that multiple cortical motor related areas are activated during monkey Bp walking, similar to that observed in humans. Furthermore, cortical inactivation studies revealed that each cortical region has an assigned functional role for the elaboration and refinements of its locomotor task. All these results show that selective yet multiple involvement of cortical motor regions are necessary for the elaboration of Bp locomotion in both humans and non-human primate models. Presumably, such multi-faceted recruitment of motor cortices is required to accommodate the limb movement and postural demands for Bp upright standing and walking. To cure locomotor dysfunctions due to CNS impairments, it is necessary to understand the CNS mechanisms involved in fine-tuning of limb movements and accompanying posture. Multi-comparative interdisciplinary studies should be initiated to reveal the CNS mechanisms involved in the control of Bp upright standing and locomotion in humans and non-human primate models.

  18. Neurodevelopmental origins of abnormal cortical morphology in dissociative identity disorder.

    Science.gov (United States)

    Reinders, A A T S; Chalavi, S; Schlumpf, Y R; Vissia, E M; Nijenhuis, E R S; Jäncke, L; Veltman, D J; Ecker, C

    2018-02-01

    To examine the two constitutes of cortical volume (CV), that is, cortical thickness (CT) and surface area (SA), in individuals with dissociative identity disorder (DID) with the view of gaining important novel insights into the underlying neurobiological mechanisms mediating DID. This study included 32 female patients with DID and 43 matched healthy controls. Between-group differences in CV, thickness, and SA, the degree of spatial overlap between differences in CT and SA, and their relative contribution to differences in regional CV were assessed using a novel spatially unbiased vertex-wise approach. Whole-brain correlation analyses were performed between measures of cortical anatomy and dissociative symptoms and traumatization. Individuals with DID differed from controls in CV, CT, and SA, with significantly decreased CT in the insula, anterior cingulate, and parietal regions and reduced cortical SA in temporal and orbitofrontal cortices. Abnormalities in CT and SA shared only about 3% of all significantly different cerebral surface locations and involved distinct contributions to the abnormality of CV in DID. Significant negative associations between abnormal brain morphology (SA and CV) and dissociative symptoms and early childhood traumatization (0 and 3 years of age) were found. In DID, neuroanatomical areas with decreased CT and SA are in different locations in the brain. As CT and SA have distinct genetic and developmental origins, our findings may indicate that different neurobiological mechanisms and environmental factors impact on cortical morphology in DID, such as early childhood traumatization. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Cardiovascular Risk and Hippocampal Thickness in Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Markus Donix

    2013-01-01

    Full Text Available Cardiovascular risk factors influence onset and progression of Alzheimer’s disease. Among cognitively healthy people, changes in brain structure and function associated with high blood pressure, diabetes, or other vascular risks suggest differential regional susceptibility to neuronal damage. In patients with Alzheimer’s disease, hippocampal and medial temporal lobe atrophy indicate early neuronal loss preferentially in key areas for learning and memory. We wanted to investigate whether this regional cortical thinning would be modulated by cardiovascular risk factors. We utilized high-resolution magnetic resonance imaging and a cortical unfolding technique to determine the cortical thickness of medial temporal subregions in 30 patients with Alzheimer’s disease. Cardiovascular risk was assessed using a sex-specific multivariable risk score. Greater cardiovascular risk was associated with cortical thinning in the hippocampus CA2/3/dentate gyrus area but not other hippocampal and medial temporal subregions. APOE genotype, a family history of Alzheimer’s disease, and age did not influence cortical thickness. Alzheimer’s disease-related atrophy could mask the influence of genetic risk factors or age on regional cortical thickness in medial temporal lobe regions, whereas the impact of vascular risk factors remains detectable. This highlights the importance of cardiovascular disease prevention and treatment in patients with Alzheimer’s disease.

  20. Cortical bone quality assessment using quantitative ultrasound on long bones.

    Science.gov (United States)

    Foiret, Josquin; Minonzio, Jean-Gabriel; Talmant, Maryline; Laugier, Pascal

    2012-01-01

    The potential of ultrasonic guided waves to identify geometrical and elastic properties of long cortical bone was tested in this feasibility study. In this paper, we present the general framework of the inversion process applied to guided waves measurements performed on test cases and on one in vitro sample of human long cortical bone (forearm). Test cases were flat plates of bone mimicking material. Cortical thickness and direction dependent elastic properties of a long cortical bone were identified from ultrasound guided waves measurements. While the results need to be confirmed on a large set of bone specimens, this study opens new perspectives for axial transmission technique, due to the fact that measurements were performed under actual conditions of clinical measurements, i.e. with a probe and a signal processing dedicated to clinical use.

  1. Proximate, Physical And Sensory Properties Of Soy-Sweet Potato ...

    African Journals Online (AJOL)

    Flour mixtures consisting of full-fat soy flour and sweet potato flour at 25-75% levels were used in cookie production. Proximate, physical and sensory properties of the cookies were determined. Physical and sensory properties investigated included thickness, diameter, spread factor, spread ratio, fragility, appearance, ...

  2. Dose-Dependent Cortical Thinning After Partial Brain Irradiation in High-Grade Glioma

    Energy Technology Data Exchange (ETDEWEB)

    Karunamuni, Roshan [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Bartsch, Hauke; White, Nathan S. [Department of Radiology, University of California San Diego, La Jolla, California (United States); Moiseenko, Vitali; Carmona, Ruben; Marshall, Deborah C.; Seibert, Tyler M. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); McDonald, Carrie R. [Department of Psychiatry, University of California San Diego, La Jolla, California (United States); Farid, Nikdokht; Krishnan, Anithapriya; Kuperman, Joshua [Department of Radiology, University of California San Diego, La Jolla, California (United States); Mell, Loren [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Brewer, James B.; Dale, Anders M. [Department of Radiology, University of California San Diego, La Jolla, California (United States); Hattangadi-Gluth, Jona A., E-mail: jhattangadi@ucsd.edu [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States)

    2016-02-01

    Purpose: Radiation-induced cognitive deficits may be mediated by tissue damage to cortical regions. Volumetric changes in cortex can be reliably measured using high-resolution magnetic resonance imaging (MRI). We used these methods to study the association between radiation therapy (RT) dose and change in cortical thickness in high-grade glioma (HGG) patients. Methods and Materials: We performed a voxel-wise analysis of MRI from 15 HGG patients who underwent fractionated partial brain RT. Three-dimensional MRI was acquired pre- and 1 year post RT. Cortex was parceled with well-validated segmentation software. Surgical cavities were censored. Each cortical voxel was assigned a change in cortical thickness between time points, RT dose value, and neuroanatomic label by lobe. Effects of dose, neuroanatomic location, age, and chemotherapy on cortical thickness were tested using linear mixed effects (LME) modeling. Results: Cortical atrophy was seen after 1 year post RT with greater effects at higher doses. Estimates from LME modeling showed that cortical thickness decreased by −0.0033 mm (P<.001) for every 1-Gy increase in RT dose. Temporal and limbic cortex exhibited the largest changes in cortical thickness per Gy compared to that in other regions (P<.001). Age and chemotherapy were not significantly associated with change in cortical thickness. Conclusions: We found dose-dependent thinning of the cerebral cortex, with varying neuroanatomical regional sensitivity, 1 year after fractionated partial brain RT. The magnitude of thinning parallels 1-year atrophy rates seen in neurodegenerative diseases and may contribute to cognitive decline following high-dose RT.

  3. Compromised cortical bone compartment in type 2 diabetes mellitus patients with microvascular disease

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram Vinod; Hansen, Stinus; Nielsen, Morten Frost Munk

    2016-01-01

    -resolution peripheral quantitative tomography (HR-pQCT) was used to assess bone structure at the non-dominant distal radius and tibia. Estimated bone strength was calculated using finite element analysis. Biochemical markers of bone turnover were measured in all participants. RESULTS: After adjusting for BMI, MVD......+ patients displayed lower cortical volumetric BMD (P=0.02) and cortical thickness (P=0.02) and higher cortical porosity at the radius (P=0.02) and a trend towards higher cortical porosity at the tibia (P=0.07) compared to controls. HR-pQCT parameters did not differ between MVD- and control subjects...

  4. Some Properties of Fuzzy Soft Proximity Spaces

    Science.gov (United States)

    Demir, İzzettin; Özbakır, Oya Bedre

    2015-01-01

    We study the fuzzy soft proximity spaces in Katsaras's sense. First, we show how a fuzzy soft topology is derived from a fuzzy soft proximity. Also, we define the notion of fuzzy soft δ-neighborhood in the fuzzy soft proximity space which offers an alternative approach to the study of fuzzy soft proximity spaces. Later, we obtain the initial fuzzy soft proximity determined by a family of fuzzy soft proximities. Finally, we investigate relationship between fuzzy soft proximities and proximities. PMID:25793224

  5. Cortical and spinal assessment

    DEFF Research Database (Denmark)

    Fischer, I W; Gram, Mikkel; Hansen, T M

    2017-01-01

    BACKGROUND: Standardized objective methods to assess the analgesic effects of opioids, enable identification of underlying mechanisms of drug actions in the central nervous system. Opioids may exert their effect on both cortical and spinal levels. In this study actions of morphine at both levels...... were investigated, followed by analysis of a possible correlation between the cortical processing and spinal transmission. METHODS: The study was conducted after a double-blinded, two-way crossover design in thirty-nine healthy participants. Each participant received 30mg morphine or placebo as oral...... morphine administration (P>0.05). CONCLUSIONS: Cold pressor EEG and the nociceptive reflex were more sensitive to morphine analgesia than resting EEG and can be used as standardized objective methods to assess opioid effects. However, no correlation between the analgesic effect of morphine on the spinal...

  6. PROXIMITY MANAGEMENT IN CRISIS CONDITIONS

    Directory of Open Access Journals (Sweden)

    Ion Dorin BUMBENECI

    2010-01-01

    Full Text Available The purpose of this study is to evaluate the level of assimilation for the terms "Proximity Management" and "Proximity Manager", both in the specialized literature and in practice. The study has two parts: the theoretical research of the two terms, and an evaluation of the use of Proximity management in 32 companies in Gorj, Romania. The object of the evaluation resides in 27 companies with less than 50 employees and 5 companies with more than 50 employees.

  7. Acute hypotension induced by aortic clamp vs. PTH provokes distinct proximal tubule Na+ transporter redistribution patterns

    DEFF Research Database (Denmark)

    Leong, Patrick K K; Yang, Li E; Lin, Harrison W

    2004-01-01

    in renal cortical membranes fractionated on sorbitol density gradients. Aortic clamp-induced acute hypotension (from 100 +/- 3 to 78 +/- 2 mmHg) provoked a 62% decrease in urine output and a significant decrease in volume flow from the proximal tubule detected as a 66% decrease in endogenous lithium......-density membranes enriched in apical markers. PTH at much lower doses (

  8. Longitudinal quantitative MRI assessment of cortical damage in multiple sclerosis: A pilot study.

    Science.gov (United States)

    Gracien, René-Maxime; Reitz, Sarah C; Hof, Stephanie-Michelle; Fleischer, Vinzenz; Droby, Amgad; Wahl, Mathias; Steinmetz, Helmuth; Groppa, Sergiu; Deichmann, Ralf; Klein, Johannes C

    2017-11-01

    Quantitative MRI (qMRI) allows assessing cortical pathology in multiple sclerosis (MS) on a microstructural level, where cortical damage has been shown to prolong T1 -relaxation time and increase proton density (PD) compared to controls. However, the evolution of these changes in MS over time has not been investigated so far. In this pilot study we used an advanced method for the longitudinal assessment of cortical tissue change in MS patients with qMRI in comparison to cortical atrophy, as derived from conventional MRI. Twelve patients with relapsing-remitting MS underwent 3T T1 /PD-mapping at two timepoints with a mean interval of 12 months. The respective cortical T1 /PD-values were extracted from the middle of the cortical layer and the cortical thickness was measured for surface-based identification of clusters with increasing/decreasing values. Statistical analysis showed clusters with increasing PD- and T1 -values over time (annualized rate for T1 /PD increase in these clusters: 3.4 ± 2.56% for T1 , P = 0.0007; 2.3 ± 2.59% for PD, P = 0.01). Changes are heterogeneous across the cortex and different patterns of longitudinal PD and T1 increase emerged. Analysis of the cortical thickness yielded only one small cluster indicating a decrease of cortical thickness. Changes of cortical tissue composition in MS seem to be reflected by a spatially inhomogeneous, multifocal increase of the PD values, indicating replacement of neural tissue by water, and of the T1 -relaxation time, a surrogate of demyelination, axonal loss, and gliosis. qMRI changes were more prominent than cortical atrophy, showing the potential of qMRI techniques to quantify microstructural alterations that remain undetected by conventional MRI. 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1485-1490. © 2017 International Society for Magnetic Resonance in Medicine.

  9. Age-dependent cortical thinning of peripheral visual field representations in primary visual cortex

    Directory of Open Access Journals (Sweden)

    Joseph Caleb Griffis

    2016-10-01

    Full Text Available The cerebral cortex changes throughout the lifespan, and the cortical grey matter in many brain regions becomes thinner with advancing age. Effects of aging on cortical thickness have been observed in many brain regions, including areas involved in basic perceptual functions such as processing visual inputs. An important property of early visual cortices is their topographic organization – the cortical structure of early visual areas forms a topographic map of retinal inputs. Primary visual cortex (V1 is considered to be the most basic cortical area in the visual processing hierarchy, and is topographically organized from posterior (central visual representation to anterior (peripheral visual representation along the calcarine sulcus. Some studies have reported strong age-dependent cortical thinning in portions of V1 that likely correspond to peripheral visual representations, while there is less evidence of substantial cortical thinning in central V1. However, the effect of aging on cortical thickness in V1 as a function of its topography has not been directly investigated. To address this gap in the literature, we estimated the cortical thickness of different eccentricity sectors in V1 using T1-weighted MRI scans acquired from groups of healthy younger and older adults, and then assessed whether between-group differences in V1 cortical thickness depended on cortical eccentricity. These analyses revealed age-dependent cortical thinning specific to peripheral visual field representations in anterior portions of V1, but did not provide evidence for age-dependent cortical thinning in other portions of V1. Additional analyses found similar effects when analyses were restricted to the gyral crown, sulcul depth, and sulcul wall, indicating that these effects are not likely due to differences in gyral/sulcul contributions to our regions of interest. Importantly, this finding indicates that age-dependent changes in cortical structure may differ among

  10. Cranial vault thickness in primates: Homo erectus does not have uniquely thick vault bones.

    Science.gov (United States)

    Copes, Lynn E; Kimbel, William H

    2016-01-01

    Extremely thick cranial vaults have been noted as a diagnostic characteristic of Homo erectus since the first fossil of the species was identified, but relatively little work has been done on elucidating its etiology or variation across fossils, living humans, or extant non-human primates. Cranial vault thickness (CVT) is not a monolithic trait, and the responsiveness of its layers to environmental stimuli is unknown. We obtained measurements of cranial vault thickness in fossil hominins from the literature and supplemented those data with additional measurements taken on African fossil specimens. Total CVT and the thickness of the cortical and diploë layers individually were compared to measures of CVT in extant species measured from more than 500 CT scans of human and non-human primates. Frontal and parietal CVT in fossil primates was compared to a regression of CVT on cranial capacity calculated for extant species. Even after controlling for cranial capacity, African and Asian H. erectus do not have uniquely high frontal or parietal thickness residuals, either among hominins or extant primates. Extant primates with residual CVT thickness similar to or exceeding H. erectus (depending on the sex and bone analyzed) include Nycticebus coucang, Perodicticus potto, Alouatta caraya, Lophocebus albigena, Galago alleni, Mandrillus sphinx, and Propithecus diadema. However, the especially thick vaults of extant non-human primates that overlap with H. erectus values are composed primarily of cortical bone, while H. erectus and other hominins have diploë-dominated vault bones. Thus, the combination of thick vaults comprised of a thickened diploë layer may be a reliable autapomorphy for members of the genus Homo. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Attention-deficit/hyperactivity disorder is characterized by a delay in cortical maturation.

    Science.gov (United States)

    Shaw, P; Eckstrand, K; Sharp, W; Blumenthal, J; Lerch, J P; Greenstein, D; Clasen, L; Evans, A; Giedd, J; Rapoport, J L

    2007-12-04

    There is controversy over the nature of the disturbance in brain development that underpins attention-deficit/hyperactivity disorder (ADHD). In particular, it is unclear whether the disorder results from a delay in brain maturation or whether it represents a complete deviation from the template of typical development. Using computational neuroanatomic techniques, we estimated cortical thickness at >40,000 cerebral points from 824 magnetic resonance scans acquired prospectively on 223 children with ADHD and 223 typically developing controls. With this sample size, we could define the growth trajectory of each cortical point, delineating a phase of childhood increase followed by adolescent decrease in cortical thickness (a quadratic growth model). From these trajectories, the age of attaining peak cortical thickness was derived and used as an index of cortical maturation. We found maturation to progress in a similar manner regionally in both children with and without ADHD, with primary sensory areas attaining peak cortical thickness before polymodal, high-order association areas. However, there was a marked delay in ADHD in attaining peak thickness throughout most of the cerebrum: the median age by which 50% of the cortical points attained peak thickness for this group was 10.5 years (SE 0.01), which was significantly later than the median age of 7.5 years (SE 0.02) for typically developing controls (log rank test chi(1)(2) = 5,609, P processes including attention and motor planning. Neuroanatomic documentation of a delay in regional cortical maturation in ADHD has not been previously reported.

  12. Gyral net: A new representation of cortical folding organization.

    Science.gov (United States)

    Chen, Hanbo; Li, Yujie; Ge, Fangfei; Li, Gang; Shen, Dinggang; Liu, Tianming

    2017-12-01

    One distinct feature of the cerebral cortex is its convex (gyri) and concave (sulci) folding patterns. Due to the remarkable complexity and variability of gyral/sulcal shapes, it has been challenging to quantitatively model their organization patterns. Inspired by the observation that the lines of gyral crests can form a connected graph on each brain hemisphere, we propose a new representation of cortical gyri/sulci organization pattern - gyral net, which models cortical architecture from a graph perspective, starting with nodes and edges obtained from the reconstructed cortical surfaces. A novel computational framework is developed to efficiently and automatically construct gyral nets from surface meshes, and four measurements are devised to quantify the folding patterns. Using an MRI dataset for autism study as a test bed, we identified reduced local connectivity cost and increased curviness of gyral net bilaterally on the parietal lobe, occipital lobe, and temporal lobe in autistic patients. Additionally, we found that the cortical thickness and the gyral straightness of gyral joints are higher than the rest of gyral crest regions. The proposed representation offers a new tool for a comprehensive and reliable characterization of the cortical folding organization. This novel computational framework will enable large-scale analyses of cortical folding patterns in the future. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Determinations of renal cortical and medullary oxygenation using BOLD Magnetic Resonance Imaging and selective diuretics

    Science.gov (United States)

    Warner, Lizette; Glockner, James F.; Woollard, John; Textor, Stephen C.; Romero, Juan C.; Lerman, Lilach O.

    2010-01-01

    Objective This study was undertaken to test the hypothesis that blood O2 level dependent magnetic resonance imaging (BOLD MRI) can detect changes in cortical proximal tubule (PT) and medullary thick ascending limb of Henle (TAL) oxygenation consequent to successive administration of furosemide and acetazolamide (Az). Assessment of PT and TAL function could be useful to monitor renal disease states in vivo. Therefore, the adjunct use of diuretics that inhibit Na+ reabsorption selectively in PT and TAL, Az and furosemide, respectively, may help discern tubular function by using BOLD MRI to detect changes in tissue oxygenation. Material and Methods BOLD MRI signal R2* (inversely related to oxygenation) and tissue oxygenation with intrarenal O2 probes were measured in pigs that received either furosemide (0.5mg/kg) or Az (15mg/kg) alone, Az sequentially after furosemide (n=6 each, 15-minute intervals), or only saline vehicle (n=3). Results R2* decreased in the cortex of Az-treated and medulla of furosemide-treated kidneys, corresponding to an increase in their tissue O2 assessed with probes. However, BOLD MRI also showed decreased cortical R2* following furosemide that was additive to the Az-induced decrease. Az administration, both alone and after furosemide, also decreased renal blood flow (−26±3.5 and −29.2±3%, respectively, pdiuretics is detectable by BOLD MRI, but may be complicated by hemodynamic effects of the drugs. Therefore, the BOLD MRI signal may reflect functional changes additional to oxygenation, and needs to be interpreted cautiously. PMID:20856128

  14. Evaluation of topology correction methods for the generation of the cortical surface

    Science.gov (United States)

    Li, Wen; Magnotta, Vincent A.

    2009-02-01

    The cerebral cortex is a highly convoluted anatomical structure. The folding pattern defined by sulci and gyri is a complex pattern that is very heterogeneous across subjects. The heterogeneity across subjects has made the automated labeling of this structure into its constituent components a challenge to the field of neuroimaging. One way to approach this problem is to conformally map the surface to another representation such as a plane or sphere. Conformal mapping of the surface requires that surface to be topologically correct. However, noise and partial volume artifacts in the MR images frequently cause holes or handles to exist in the surface that must be removed. Topology correction techniques have been proposed that operate on the cortical surface, the original image data, and hybrid methods have been proposed. This paper presents an experimental assessment of two different topology correction methods. The first approach is based on modification of 3D voxel data. The second method is a hybrid approach that determines the location of defects from the surface representation while repairing the surface by modifying the underlying image data. These methods have been applied to 10 brains, and a comparison is made among them. In addition, detailed statistics are given based on the voxel correction method. Based on these 10 MRI datasets, we have found the hybrid method incapable of correcting the cortical surface appropriately when a handles and holes exist in close proximity. In several cases, holes in the anatomical surface were labeled as handles thus resulting in discontinuities in the folding pattern. The image-based approach in this study was found to correct the topology in all ten cases within a reasonable time. Furthermore, the distance between the original and corrected surfaces, thickness of brain cortex, curvatures and surface areas are provided as assessments of the approach based on our datasets.

  15. Immediate intensive mobilization compared with immediate conventional mobilization for the impacted osteoporotic conservatively treated proximal humeral fracture: a randomized controlled trial.

    Science.gov (United States)

    Carbone, S; Razzano, C; Albino, P; Mezzoprete, R

    2017-12-01

    To select in a 2-year survey of proximal humerus fractures accessing the emergency department, a population of osteoporotic stable impacted fractures and to randomize them into two groups, one with an immediate intensive mobilization program and the other with an immediate conventional mobilization program. In emergency department, patients with clinical signs of shoulder girdle fracture were submitted to standard X-ray examination and CT scan. Patients with stable (absence of metaphyseal comminution or fifth fragment) osteoporotic (cortical bone thickness lower than 6 mm) impacted (Is any part of metaphysis or head impacted into the shaft? YES/NO) proximal humerus fractures were selected for randomization in one of the two groups. Group 1: early intensive mobilization; Group 2: early conventional mobilization. Functional and radiographic assessment was recorded at 3, 6 and 12 months of follow-up. In the considered period, 120 patients were affected by a stable impacted osteoporotic proximal humerus fracture. At the final follow-up, 36 patients in group 1 and 39 patients in group 2 were available for statistical analysis. Functional and radiographic scores were comparable, with a trend of significance in favor of group 2. No fracture in any of the group showed significant loss of reduction respect to 6 months of follow-up. 4 (10%) and 1 (2.5%) patients in groups 1 and 2 were not compliant with the rehabilitation program (p = 0.037). This randomized controlled trial showed that impacted osteoporotic proximal humerus fractures can be managed non-operatively with an early conventional rehabilitation program composed by 10 sessions of passive motion twice a week, followed by recovery of active range of motion for further 10 sessions thrice a week, while no advantage is given by a more aggressive rehabilitation regimen. Self-assisted exercises should be explained to patients to maximize the effects of the assisted program. Level 1, randomized controlled double

  16. Cortical pathology in multiple sclerosis.

    Science.gov (United States)

    Stadelmann, Christine; Albert, Monika; Wegner, Christiane; Brück, Wolfgang

    2008-06-01

    Multiple sclerosis is the most common chronic, disabling central nervous system disease in young adults, characterized by inflammatory demyelinating white matter lesions with glial scar formation and axonal loss. Lately, evidence has accumulated that large areas of grey matter are affected in multiple sclerosis patients. Findings in post-mortem brain tissue support the notion that cortical demyelination is frequent and extensive, especially in patients with chronic multiple sclerosis. Cortical lesions differ from white matter lesions with respect to inflammatory cell infiltration, gliosis, and remyelination. Thus, differences in cortical and white matter lesion pathogenesis have been proposed. Experimental models suggest a decisive role for antimyelin antibodies in cortical demyelination. Topical studies focus on damage to neurons, dendrites, and synapses in cortical multiple sclerosis lesions. Improved imaging techniques for the detection of cortical lesions are currently developed and will provide the basis for future clinicopathological correlative studies. In summary, recent years have opened our eyes to the extensive grey matter involvement in multiple sclerosis. Studies on the pathogenesis of cortical demyelination, cortical damage, and repair will elucidate basic principles of multiple sclerosis lesion formation. However, more sensitive imaging tools are required to study the impact of cortical lesions on clinical symptoms, disability, and disease progression.

  17. Abnormalities of hippocampal-cortical connectivity in temporal lobe epilepsy patients with hippocampal sclerosis

    Science.gov (United States)

    Li, Wenjing; He, Huiguang; Lu, Jingjing; Wang, Chunheng; Li, Meng; Lv, Bin; Jin, Zhengyu

    2011-03-01

    Hippocampal sclerosis (HS) is the most common damage seen in the patients with temporal lobe epilepsy (TLE). In the present study, the hippocampal-cortical connectivity was defined as the correlation between the hippocampal volume and cortical thickness at each vertex throughout the whole brain. We aimed to investigate the differences of ipsilateral hippocampal-cortical connectivity between the unilateral TLE-HS patients and the normal controls. In our study, the bilateral hippocampal volumes were first measured in each subject, and we found that the ipsilateral hippocampal volume significantly decreased in the left TLE-HS patients. Then, group analysis showed significant thinner average cortical thickness of the whole brain in the left TLE-HS patients compared with the normal controls. We found significantly increased ipsilateral hippocampal-cortical connectivity in the bilateral superior temporal gyrus, the right cingulate gyrus and the left parahippocampal gyrus of the left TLE-HS patients, which indicated structural vulnerability related to the hippocampus atrophy in the patient group. However, for the right TLE-HS patients, no significant differences were found between the patients and the normal controls, regardless of the ipsilateral hippocampal volume, the average cortical thickness or the patterns of hippocampal-cortical connectivity, which might be related to less atrophies observed in the MRI scans. Our study provided more evidence for the structural abnormalities in the unilateral TLE-HS patients.

  18. Altered cortical anatomical networks in temporal lobe epilepsy

    Science.gov (United States)

    Lv, Bin; He, Huiguang; Lu, Jingjing; Li, Wenjing; Dai, Dai; Li, Meng; Jin, Zhengyu

    2011-03-01

    Temporal lobe epilepsy (TLE) is one of the most common epilepsy syndromes with focal seizures generated in the left or right temporal lobes. With the magnetic resonance imaging (MRI), many evidences have demonstrated that the abnormalities in hippocampal volume and the distributed atrophies in cortical cortex. However, few studies have investigated if TLE patients have the alternation in the structural networks. In the present study, we used the cortical thickness to establish the morphological connectivity networks, and investigated the network properties using the graph theoretical methods. We found that all the morphological networks exhibited the small-world efficiency in left TLE, right TLE and normal groups. And the betweenness centrality analysis revealed that there were statistical inter-group differences in the right uncus region. Since the right uncus located at the right temporal lobe, these preliminary evidences may suggest that there are topological alternations of the cortical anatomical networks in TLE, especially for the right TLE.

  19. Fractures of the proximal humerus

    DEFF Research Database (Denmark)

    Brorson, Stig

    2013-01-01

    . The bandages were further supported by splints made of wood or coarse grass. Healing was expected in forty days. Different fracture patterns have been discussed and classified since Ancient Greece. Current classification of proximal humeral fractures mainly relies on the classifications proposed by Charles......, classification of proximal humeral fractures remains a challenge for the conduct, reporting, and interpretation of clinical trials. The evidence for the benefits of surgery in complex fractures of the proximal humerus is weak. In three systematic reviews I studied the outcome after locking plate osteosynthesis......Fractures of the proximal humerus have been diagnosed and managed since the earliest known surgical texts. For more than four millennia the preferred treatment was forceful traction, closed reduction, and immobilization with linen soaked in combinations of oil, honey, alum, wine, or cerate...

  20. Cortico-cortical communication dynamics

    Directory of Open Access Journals (Sweden)

    Per E Roland

    2014-05-01

    Full Text Available IIn principle, cortico-cortical communication dynamics is simple: neurons in one cortical area communicate by sending action potentials that release glutamate and excite their target neurons in other cortical areas. In practice, knowledge about cortico-cortical communication dynamics is minute. One reason is that no current technique can capture the fast spatio-temporal cortico-cortical evolution of action potential transmission and membrane conductances with sufficient spatial resolution. A combination of optogenetics and monosynaptic tracing with virus can reveal the spatio-temporal cortico-cortical dynamics of specific neurons and their targets, but does not reveal how the dynamics evolves under natural conditions. Spontaneous ongoing action potentials also spread across cortical areas and are difficult to separate from structured evoked and intrinsic brain activity such as thinking. At a certain state of evolution, the dynamics may engage larger populations of neurons to drive the brain to decisions, percepts and behaviors. For example, successfully evolving dynamics to sensory transients can appear at the mesoscopic scale revealing how the transient is perceived. As a consequence of these methodological and conceptual difficulties, studies in this field comprise a wide range of computational models, large-scale measurements (e.g., by MEG, EEG, and a combination of invasive measurements in animal experiments. Further obstacles and challenges of studying cortico-cortical communication dynamics are outlined in this critical review.

  1. Cortical morphology of adolescents with bipolar disorder and with schizophrenia.

    Science.gov (United States)

    Janssen, Joost; Alemán-Gómez, Yasser; Schnack, Hugo; Balaban, Evan; Pina-Camacho, Laura; Alfaro-Almagro, Fidel; Castro-Fornieles, Josefina; Otero, Soraya; Baeza, Inmaculada; Moreno, Dolores; Bargalló, Nuria; Parellada, Mara; Arango, Celso; Desco, Manuel

    2014-09-01

    Recent evidence points to overlapping decreases in cortical thickness and gyrification in the frontal lobe of patients with adult-onset schizophrenia and bipolar disorder with psychotic symptoms, but it is not clear if these findings generalize to patients with a disease onset during adolescence and what may be the mechanisms underlying a decrease in gyrification. This study analyzed cortical morphology using surface-based morphometry in 92 subjects (age range 11-18 years, 52 healthy controls and 40 adolescents with early-onset first-episode psychosis diagnosed with schizophrenia (n=20) or bipolar disorder with psychotic symptoms (n=20) based on a two year clinical follow up). Average lobar cortical thickness, surface area, gyrification index (GI) and sulcal width were compared between groups, and the relationship between the GI and sulcal width was assessed in the patient group. Both patients groups showed decreased cortical thickness and increased sulcal width in the frontal cortex when compared to healthy controls. The schizophrenia subgroup also had increased sulcal width in all other lobes. In the frontal cortex of the combined patient group sulcal width was negatively correlated (r=-0.58, pschizophrenia and bipolar disorder with psychotic symptoms there is cortical thinning, decreased GI and increased sulcal width of the frontal cortex present at the time of the first psychotic episode. Decreased frontal GI is associated with the widening of the frontal sulci which may reduce sulcal surface area. These results suggest that abnormal growth (or more pronounced shrinkage during adolescence) of the frontal cortex represents a shared endophenotype for psychosis. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. The infrastructure of psychological proximity

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt

    2015-01-01

    ). The experience of psychological proximity between patient and nurse is provided through confidence, continuity and the practical set-up. This constitutes an important enactment of skillfulness, which may render telemedicine a convincing health service in the future. Methodology: The study draws on a pilot...... (Langstrup & Winthereik 2008). This study contributes by showing the infrastructure of psychological proximity, which is provided by way of device, confidence, continuity and accountability....

  3. Associations of Age, BMI, and Years of Menstruation with Proximal Femur Strength in Chinese Postmenopausal Women: A Cross-Sectional Study.

    Science.gov (United States)

    Kang, Huili; Chen, Yu-Ming; Han, Guiyuan; Huang, Hua; Chen, Wei-Qing; Wang, Xidan; Zhu, Ying-Ying; Xiao, Su-Mei

    2016-01-23

    This study aimed to elucidate the associations of age, BMI, and years of menstruation with proximal femur strength in Chinese postmenopausal women, which may improve the prediction of hip fracture risk. A cross-sectional study was conducted in 1322 Chinese postmenopausal women recruited from communities. DXA images were used to generate bone mineral density (BMD) and geometric parameters, including cross-sectional area (CSA), outer diameter (OD), cortical thickness (CT), section modulus (SM), buckling ratio (BR) at the narrow neck (NN), intertrochanter (IT), and femoral shaft (FS). Relationships of age, BMI, and years of menstruation with bone phenotypes were analyzed with the adjustment of height, age at menarche, total daily physical activity, education, smoking status, calcium tablet intake, etc. Age was associated with lower BMD, CSA, CT, SM, and higher BR (p menstruation had the positive relationships with proximal femur strength (p menstruation were 0.14%-1.34%, 0.20%-2.70%, and 0.16%-0.98%, respectively. These results supported that bone strength deteriorated with aging and enhanced with higher BMI and longer time of years of menstruation in Chinese postmenopausal women.

  4. Modeling cortical circuits.

    Energy Technology Data Exchange (ETDEWEB)

    Rohrer, Brandon Robinson; Rothganger, Fredrick H.; Verzi, Stephen J.; Xavier, Patrick Gordon

    2010-09-01

    The neocortex is perhaps the highest region of the human brain, where audio and visual perception takes place along with many important cognitive functions. An important research goal is to describe the mechanisms implemented by the neocortex. There is an apparent regularity in the structure of the neocortex [Brodmann 1909, Mountcastle 1957] which may help simplify this task. The work reported here addresses the problem of how to describe the putative repeated units ('cortical circuits') in a manner that is easily understood and manipulated, with the long-term goal of developing a mathematical and algorithmic description of their function. The approach is to reduce each algorithm to an enhanced perceptron-like structure and describe its computation using difference equations. We organize this algorithmic processing into larger structures based on physiological observations, and implement key modeling concepts in software which runs on parallel computing hardware.

  5. Cortical neural prosthetics.

    Science.gov (United States)

    Schwartz, Andrew B

    2004-01-01

    Control of prostheses using cortical signals is based on three elements: chronic microelectrode arrays, extraction algorithms, and prosthetic effectors. Arrays of microelectrodes are permanently implanted in cerebral cortex. These arrays must record populations of single- and multiunit activity indefinitely. Information containing position and velocity correlates of animate movement needs to be extracted continuously in real time from the recorded activity. Prosthetic arms, the current effectors used in this work, need to have the agility and configuration of natural arms. Demonstrations using closed-loop control show that subjects change their neural activity to improve performance with these devices. Adaptive-learning algorithms that capitalize on these improvements show that this technology has the capability of restoring much of the arm movement lost with immobilizing deficits.

  6. Progressive posterior cortical dysfunction

    Directory of Open Access Journals (Sweden)

    Fábio Henrique de Gobbi Porto

    Full Text Available Abstract Progressive posterior cortical dysfunction (PPCD is an insidious syndrome characterized by prominent disorders of higher visual processing. It affects both dorsal (occipito-parietal and ventral (occipito-temporal pathways, disturbing visuospatial processing and visual recognition, respectively. We report a case of a 67-year-old woman presenting with progressive impairment of visual functions. Neurologic examination showed agraphia, alexia, hemispatial neglect (left side visual extinction, complete Balint's syndrome and visual agnosia. Magnetic resonance imaging showed circumscribed atrophy involving the bilateral parieto-occipital regions, slightly more predominant to the right . Our aim was to describe a case of this syndrome, to present a video showing the main abnormalities, and to discuss this unusual presentation of dementia. We believe this article can contribute by improving the recognition of PPCD.

  7. Total brain, cortical and white matter volumes in children previously treated with glucocorticoids

    DEFF Research Database (Denmark)

    Holm, Sara K; Madsen, Kathrine S; Vestergaard, Martin

    2018-01-01

    BACKGROUND: Perinatal exposure to glucocorticoids and elevated endogenous glucocorticoid-levels during childhood can have detrimental effects on the developing brain. Here, we examined the impact of glucocorticoid-treatment during childhood on brain volumes. METHODS: Thirty children and adolescents...... with rheumatic or nephrotic disease previously treated with glucocorticoids and 30 controls matched on age, sex, and parent education underwent magnetic resonance imaging (MRI) of the brain. Total cortical grey and white matter, brain, and intracranial volume, and total cortical thickness and surface area were...... were mainly driven by the children with rheumatic disease. Total cortical thickness and cortical surface area did not significantly differ between groups. We found no significant associations between glucocorticoid-treatment variables and volumetric measures. CONCLUSION: Observed smaller total brain...

  8. Education and "Thick" Epistemology

    Science.gov (United States)

    Kotzee, Ben

    2011-01-01

    In this essay Ben Kotzee addresses the implications of Bernard Williams's distinction between "thick" and "thin" concepts in ethics for epistemology and for education. Kotzee holds that, as in the case of ethics, one may distinguish between "thick" and "thin" concepts of epistemology and, further, that this distinction points to the importance of…

  9. Calcium phosphate cement augmentation of cancellous bone screws can compensate for the absence of cortical fixation.

    Science.gov (United States)

    Stadelmann, Vincent A; Bretton, Elise; Terrier, Alexandre; Procter, Philip; Pioletti, Dominique P

    2010-11-16

    An obvious means to improve the fixation of a cancellous bone screw is to augment the surrounding bone with cement. Previous studies have shown that bone augmentation with Calcium Phosphate (CaP) cement significantly improves screw fixation. Nevertheless, quantitative data about the optimal distribution of CaP cement is not available. The present study aims to show the effect of cement distribution on the screw fixation strength for various cortical thicknesses and to determine the conditions at which cement augmentation can compensate for the absence of cortical fixation in osteoporotic bone. In this study, artificial bone materials were used to mimic osteoporotic cancellous bone and cortical bone of varying thickness. These bone constructs were used to test the fixation strength of cancellous bone screws in different cortical thicknesses and different cement augmentation depths. The cement distribution was measured with microCT. The maximum pullout force was measured experimentally. The microCT analysis revealed a pseudo-conic shape distribution of the cement around the screws. While the maximum pullout strength of the screws in the artificial bone only was 30±7N, it could increase up to approximately 1000N under optimal conditions. Cement augmentation significantly increased pullout force in all cases. The effect of cortical thickness on pullout force was reduced with increased cement augmentation depth. Indeed, cement augmentation without cortical fixation increased pullout forces over that of screws without cement augmentation but with cortical fixation. Since cement augmentation significantly increased pullout force in all cases, we conclude that the loss of cortical fixation can be compensated by cement augmentation. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Cortical Thinning in Network-Associated Regions in Cognitively Normal and Below-Normal Range Schizophrenia

    Directory of Open Access Journals (Sweden)

    R. Walter Heinrichs

    2017-01-01

    Full Text Available This study assessed whether cortical thickness across the brain and regionally in terms of the default mode, salience, and central executive networks differentiates schizophrenia patients and healthy controls with normal range or below-normal range cognitive performance. Cognitive normality was defined using the MATRICS Consensus Cognitive Battery (MCCB composite score (T=50 ± 10 and structural magnetic resonance imaging was used to generate cortical thickness data. Whole brain analysis revealed that cognitively normal range controls (n=39 had greater cortical thickness than both cognitively normal (n=17 and below-normal range (n=49 patients. Cognitively normal controls also demonstrated greater thickness than patients in regions associated with the default mode and salience, but not central executive networks. No differences on any thickness measure were found between cognitively normal range and below-normal range controls (n=24 or between cognitively normal and below-normal range patients. In addition, structural covariance between network regions was high and similar across subgroups. Positive and negative symptom severity did not correlate with thickness values. Cortical thinning across the brain and regionally in relation to the default and salience networks may index shared aspects of the psychotic psychopathology that defines schizophrenia with no relation to cognitive impairment.

  11. Cortical-Cortical Interactions And Sensory Information Processing in Autism

    Science.gov (United States)

    2008-04-30

    Additionally, these cortical areas have been implicated from significantly elevated TOJ thresholds (worse performance) in subjects with dyslexia [5...of the fact that above-average TOJ thresholds occur in subjects with known damage to these same cortical areas ( dyslexia [5], dystonia [6-8], and...volumes in autistic boys . Brain 2003, 126:1182-1192. 32. Hollander E, Anagnostou E, Chaplin W, Esposito K, Haznedar MM, Licalzi E, Wasserman S, Soorya L

  12. In Vivo Characterization of Cortical Bone Using Guided Waves Measured by Axial Transmission.

    Science.gov (United States)

    Vallet, Quentin; Bochud, Nicolas; Chappard, Christine; Laugier, Pascal; Minonzio, Jean-Gabriel

    2016-09-01

    Cortical bone loss is not fully assessed by the current X-ray methods, and there is an unmet need in identifying women at risk of osteoporotic fracture, who should receive a treatment. The last decade has seen the emergence of the ultrasound (US) axial transmission (AT) techniques to assess a cortical bone. Recent AT techniques exploit the multimode waveguide response of the long bones such as the radius. A recent ex vivo study by our group evidenced that a multimode AT approach can yield simultaneous estimates of cortical thickness (Ct.Th) and stiffness. The aim of this paper is to move one step forward to evaluate the feasibility of measuring multimode guided waves (GW) in vivo and to infer from it cortical thickness. Measurements were taken on the forearm of 14 healthy subjects with the goal to test the accuracy of the estimated thickness using the bidirectional AT method implemented on a dedicated 1-MHz linear US array. This setup allows determining in vivo the dispersion curves of GW transmitted in the cortical layer of the radius. An inverse procedure based on the comparison between the measured and modeled dispersion curves predicted by a 2-D transverse isotropic free plate waveguide model allowed an estimation of cortical thickness, despite the presence of soft tissue. The Ct.Th values were validated by comparison with the site-matched estimates derived from X-ray high-resolution peripheral quantitative computed tomography. Results showed a significant correlation between both measurements ( r2 = 0.7 , , and [Formula: see text] mm). This pilot study demonstrates the potential of bidirectional AT for the in vivo assessment of cortical thickness, a bone strength-related factor.

  13. Adult Intramedullary Ewing Sarcoma of the Proximal Hip

    Directory of Open Access Journals (Sweden)

    Preetam Gongidi

    2014-01-01

    Full Text Available Ewing sarcoma of bone is classically a permeative lesion in the diaphysis of long bones in children. While they occur primarily in children and adolescents, they can be seen in young adults in their 20s, but these are typically seen in flat bones. The permeative nature of the lesion can elicit new bone formation creating a partially sclerotic appearance, cortical expansion presenting as a “Codman triangle,” or have an “onion-skin” type of aggressive periosteal reaction/periostitis. Ewing sarcoma is rarely seen without an associated soft-tissue mass and is even rarer to just have benign-appearing periostitis (e.g., thick, uniform, or wavy cortex. We present such a case of Ewing sarcoma in a young adult confined to just the medullary metadiaphysis without cortical erosion or soft-tissue mass. To the best of our knowledge, this is the first case to be reported in the radiology literature.

  14. Longitudinal MR cortical thinning of individuals and its correlation with PET metabolic reduction: a measurement consistency and correctness studies

    Science.gov (United States)

    Lin, Zhongmin S.; Avinash, Gopal; McMillan, Kathryn; Yan, Litao; Minoshima, Satoshi

    2014-03-01

    Cortical thinning and metabolic reduction can be possible imaging biomarkers for Alzheimer's disease (AD) diagnosis and monitoring. Many techniques have been developed for the cortical measurement and widely used for the clinical statistical studies. However, the measurement consistency of individuals, an essential requirement for a clinically useful technique, requires proper further investigation. Here we leverage our previously developed BSIM technique 1 to measure cortical thickness and thinning and use it with longitudinal MRI from ADNI to investigate measurement consistency and spatial resolution. 10 normal, 10 MCI, and 10 AD subjects in their 70s were selected for the study. Consistent cortical thinning patterns were observed in all baseline and follow up images. Rapid cortical thinning was shown in some MCI and AD cases. To evaluate the correctness of the cortical measurement, we compared longitudinal cortical thinning with clinical diagnosis and longitudinal PET metabolic reduction measured using 3D-SSP technique2 for the same person. Longitudinal MR cortical thinning and corresponding PET metabolic reduction showed high level pattern similarity revealing certain correlations worthy of further studies. Severe cortical thinning that might link to disease conversion from MCI to AD was observed in two cases. In summary, our results suggest that consistent cortical measurements using our technique may provide means for clinical diagnosis and monitoring at individual patient's level and MR cortical thinning measurement can complement PET metabolic reduction measurement.

  15. Adolescent brain maturation and cortical folding: evidence for reductions in gyrification.

    Directory of Open Access Journals (Sweden)

    Daniel Klein

    Full Text Available Evidence from anatomical and functional imaging studies have highlighted major modifications of cortical circuits during adolescence. These include reductions of gray matter (GM, increases in the myelination of cortico-cortical connections and changes in the architecture of large-scale cortical networks. It is currently unclear, however, how the ongoing developmental processes impact upon the folding of the cerebral cortex and how changes in gyrification relate to maturation of GM/WM-volume, thickness and surface area. In the current study, we acquired high-resolution (3 Tesla magnetic resonance imaging (MRI data from 79 healthy subjects (34 males and 45 females between the ages of 12 and 23 years and performed whole brain analysis of cortical folding patterns with the gyrification index (GI. In addition to GI-values, we obtained estimates of cortical thickness, surface area, GM and white matter (WM volume which permitted correlations with changes in gyrification. Our data show pronounced and widespread reductions in GI-values during adolescence in several cortical regions which include precentral, temporal and frontal areas. Decreases in gyrification overlap only partially with changes in the thickness, volume and surface of GM and were characterized overall by a linear developmental trajectory. Our data suggest that the observed reductions in GI-values represent an additional, important modification of the cerebral cortex during late brain maturation which may be related to cognitive development.

  16. Cubesat Proximity Operations Demonstration (CPOD)

    Science.gov (United States)

    Villa, Marco; Martinez, Andres; Petro, Andrew

    2015-01-01

    The CubeSat Proximity Operations Demonstration (CPOD) project will demonstrate rendezvous, proximity operations and docking (RPOD) using two 3-unit (3U) CubeSats. Each CubeSat is a satellite with the dimensions 4 inches x 4 inches x 13 inches (10 centimeters x 10 centimeters x 33 centimeters) and weighing approximately 11 pounds (5 kilograms). This flight demonstration will validate and characterize many new miniature low-power proximity operations technologies applicable to future missions. This mission will advance the state of the art in nanosatellite attitude determination,navigation and control systems, in addition to demonstrating relative navigation capabilities.The two CPOD satellites are scheduled to be launched together to low-Earth orbit no earlier than Dec. 1, 2015.

  17. Posterior cortical atrophy.

    Science.gov (United States)

    Zakzanis, K K; Boulos, M I

    2001-11-01

    The term posterior cortical atrophy (PCA) was introduced in 1988 to describe five patients with fairly homogeneous, but otherwise unclassified, symptoms. These patients showed signs of a slowly progressive dementia bearing behavioral and physiologic similarities to Alzheimer's disease, but with notable distinctions. Specifically, PCA is characterized by an early onset of visual agnosia, followed by some or all components of Balint's syndrome, Gerstmann's syndrome, and transcortical sensory aphasia. In this review, the history, epidemiology, pathophysiology, neurobehavioral aspects, assessment (including neurologic and neuropsychologic), differential diagnosis, and treatment recommendations for this disorder are reviewed. As originally defined, PCA appears to be a clinically homogeneous syndrome. The cluster of symptoms that are common to virtually all examined cases evidences this. Although the behavioral and cognitive properties of the disorder are well established, many aspects of PCA remain unclear. Specifically, available research and understanding of PCA epidemiology and treatment are highly inadequate. In fact, the majority of such information regarding PCA is derived from studies of Alzheimer's disease. To a lesser extent, Pick's disease and Creutzfeldt-Jakob disease research have also provided insight into the underpinnings of PCA. Until PCA is categorically defined as a variant or subgroup of these other neurodegenerative disorders, however, such derivations are merely speculations.

  18. Prediction for human intelligence using morphometric characteristics of cortical surface: partial least square analysis.

    Science.gov (United States)

    Yang, J-J; Yoon, U; Yun, H J; Im, K; Choi, Y Y; Lee, K H; Park, H; Hough, M G; Lee, J-M

    2013-08-29

    A number of imaging studies have reported neuroanatomical correlates of human intelligence with various morphological characteristics of the cerebral cortex. However, it is not yet clear whether these morphological properties of the cerebral cortex account for human intelligence. We assumed that the complex structure of the cerebral cortex could be explained effectively considering cortical thickness, surface area, sulcal depth and absolute mean curvature together. In 78 young healthy adults (age range: 17-27, male/female: 39/39), we used the full-scale intelligence quotient (FSIQ) and the cortical measurements calculated in native space from each subject to determine how much combining various cortical measures explained human intelligence. Since each cortical measure is thought to be not independent but highly inter-related, we applied partial least square (PLS) regression, which is one of the most promising multivariate analysis approaches, to overcome multicollinearity among cortical measures. Our results showed that 30% of FSIQ was explained by the first latent variable extracted from PLS regression analysis. Although it is difficult to relate the first derived latent variable with specific anatomy, we found that cortical thickness measures had a substantial impact on the PLS model supporting the most significant factor accounting for FSIQ. Our results presented here strongly suggest that the new predictor combining different morphometric properties of complex cortical structure is well suited for predicting human intelligence. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  19. Initial cognitive decline is associated with cortical thinning in early Parkinson disease.

    Science.gov (United States)

    Pereira, Joana B; Svenningsson, Per; Weintraub, Daniel; Brønnick, Kolbjørn; Lebedev, Alexander; Westman, Eric; Aarsland, Dag

    2014-06-03

    Our aim was to assess cortical thickness in a large multicenter cohort of drug-naive patients with early Parkinson disease (PD), with and without mild cognitive impairment (MCI), and explore the cognitive correlates of regional cortical thinning. One hundred twenty-three newly diagnosed patients with PD and 56 healthy controls with 3-tesla structural MRI scans and complete neuropsychological assessment from the Parkinson's Progression Markers Initiative were included. Modified Movement Disorders Society Task Force level II criteria were applied to diagnose MCI in PD. FreeSurfer image processing and analysis software was used to measure cortical thickness across groups and the association with cognitive domains and tests. In patients with MCI, atrophy was found in temporal, parietal, frontal, and occipital areas compared with controls. Specific regional thinning in the right inferior temporal cortex was also found in cognitively normal patients. Memory, executive, and visuospatial performance was associated with temporoparietal and superior frontal thinning, suggesting a relationship between cognitive impairment and both anterior and posterior cortical atrophy in the whole patient sample. These findings confirm that MCI is associated with widespread cortical atrophy. In addition, they suggest that regional cortical thinning is already present at the time of diagnosis in patients with early, untreated PD who do not meet the criteria for MCI. Together, the results indicate that cortical thinning can serve as a marker for initial cognitive decline in early PD. © 2014 American Academy of Neurology.

  20. Classification of Cortical Brain Malformations

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2008-03-01

    Full Text Available Clinical, radiological, and genetic classifications of 113 cases of malformations of cortical development (MCD were evaluated at the Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, the Netherlands.

  1. Ocean Sediment Thickness Contours

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean sediment thickness contours in 200 meter intervals for water depths ranging from 0 - 18,000 meters. These contours were derived from a global sediment...

  2. Osteoblastoma-like Osteosarcoma of the Proximal Tibia: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Soon Young; Kim, Mi Sung; Park, Noh Hyuck; Park, Chan Sub [Dept. of Radiology, Myoungji Hospital, Kwandong University College of Medicine, Goyang (Korea, Republic of); Park, Hee Jin [Dept. of Radiology, Kangbuk Samsung, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Yi, Sng Yeop [Dept. of Pathology, Myoungji Hospital, Kwandong University College of Medicine, Goyang (Korea, Republic of); Kim, Hyung Soo [Dept. of Orthpedic Surgery, Myoungji Hospital, Kwandong University College of Medicine, Goyang (Korea, Republic of)

    2011-05-15

    Osteoblastoma-like osteosarcoma is a rare, low-grade variant of osteosarcoma that may resemble osteoblastoma clinically, radiographically and histologically. We report a case of osteoblastoma-like osteosarcoma in the right proximal tibia in a 17-year-old woman. Plain radiography revealed an irregular osteolytic lesion in the metaepiphysis of the right proximal tibia and transverse fracture line of the metaphysic through an osteolytic lesion. MRI showed well-defined mass confined to the medullary space with cortical disruption and pathologic fracture. The MR signals were low on T1-weighted image and intermediate on T2-weighted image.

  3. Influence of Screw Length and Bone Thickness on the Stability of Temporary Implants

    Science.gov (United States)

    Fernandes, Daniel Jogaib; Elias, Carlos Nelson; Ruellas, Antônio Carlos de Oliveira

    2015-01-01

    The purpose of this work was to study the influence of screw length and bone thickness on the stability of temporary implants. A total of 96 self-drilling temporary screws with two different lengths were inserted into polyurethane blocks (n = 66), bovine femurs (n = 18) and rabbit tibia (n = 12) with different cortical thicknesses (1 to 8 mm). Screws insertion in polyurethane blocks was assisted by a universal testing machine, torque peaks were collected by a digital torquemeter and bone thickness was monitored by micro-CT. The results showed that the insertion torque was significantly increased with the thickness of cortical bone from polyurethane (p < 0.0001), bovine (p = 0.0035) and rabbit (p < 0.05) sources. Cancellous bone improved significantly the mechanical implant stability. Insertion torque and insertion strength was successfully moduled by equations, based on the cortical/cancellous bone behavior. Based on the results, insertion torque and bone strength can be estimate in order to prevent failure of the cortical layer during temporary screw placement. The stability provided by a cortical thickness of 2 or 1 mm coupled to cancellous bone was deemed sufficient for temporary implants stability. PMID:28793582

  4. Influence of Screw Length and Bone Thickness on the Stability of Temporary Implants

    Directory of Open Access Journals (Sweden)

    Daniel Jogaib Fernandes

    2015-09-01

    Full Text Available The purpose of this work was to study the influence of screw length and bone thickness on the stability of temporary implants. A total of 96 self-drilling temporary screws with two different lengths were inserted into polyurethane blocks (n = 66, bovine femurs (n = 18 and rabbit tibia (n = 12 with different cortical thicknesses (1 to 8 mm. Screws insertion in polyurethane blocks was assisted by a universal testing machine, torque peaks were collected by a digital torquemeter and bone thickness was monitored by micro-CT. The results showed that the insertion torque was significantly increased with the thickness of cortical bone from polyurethane (p < 0.0001, bovine (p = 0.0035 and rabbit (p < 0.05 sources. Cancellous bone improved significantly the mechanical implant stability. Insertion torque and insertion strength was successfully moduled by equations, based on the cortical/cancellous bone behavior. Based on the results, insertion torque and bone strength can be estimate in order to prevent failure of the cortical layer during temporary screw placement. The stability provided by a cortical thickness of 2 or 1 mm coupled to cancellous bone was deemed sufficient for temporary implants stability.

  5. Comparison of equine articular cartilage thickness in various joints.

    Science.gov (United States)

    Lee, Hyeon; Kirkland, W Grant; Whitmore, Ryan N; Theis, Kelcie M; Young, Hannah E; Richardson, Ashton J; Jackson, Robert L; Hanson, R Reid

    2014-01-01

    Thicknesses of fresh equine articular cartilage surfaces from the fetlock, carpal and stifle joints were measured employing a needle probe test. Eighty-seven samples used in measurement were cultivated from fetlock, carpal and stifle joints of 12 deceased within 4 h of death. After approximately three minutes of exposure to air during dissection, all cartilage samples were preserved in a saline solution to keep the articular cartilage hydrated for testing. The thickness was measured on five different spots on the same sample. The thicknesses of the fetlock, carpus and stifle were compared. The articular cartilage of the stifle was thicker than the fetlock and carpus, while the fetlock and the carpus had similar thickness values. The average thickness of the fetlock, carpal and stifle joint are 0.86, 0.87 and 2.1 mm, respectively. They were statistically compared using the Student t-test. The differences on the articular cartilage thicknesses between the fetlock and stifle, and carpus and stifle were "very highly significant" (p fetlock and carpus. Four different surfaces in the fetlock and four in the carpal joint were also compared. Significant differences between each set of the four surfaces were not observed. In the carpus, the difference in thickness between the distal radius and proximal third carpal bone articular cartilage surfaces as well as the proximal radial carpal bone and distal radial carpal bone articular cartilage surfaces were statistically significant.

  6. Hiperostosis cortical infantil

    Directory of Open Access Journals (Sweden)

    Salvador Javier Santos Medina

    2015-04-01

    Full Text Available La enfermedad de Caffey, o hiperostosis cortical infantil, es una rara enfermedad ósea autolimitada, que aparece de preferencia en lactantes con signos inespecíficos sistémicos; el más relevante es la reacción subperióstica e hiperostosis en varios huesos del cuerpo, con predilección en el 75-80 % de los casos por la mandíbula. Su pronóstico es bueno, la mayoría no deja secuelas. El propósito del presente trabajo es describir las características clínicas, presentes en un lactante de cinco meses de edad, atendido en el Hospital Pediátrico Provincial “Mártires de Las Tunas” con este diagnóstico, quien ingresó en el servicio de miscelánea B por una celulitis facial. Presentaba aumento de volumen en la región geniana izquierda, febrícola e inapetencia. Se impuso tratamiento con cefazolina y se egresó a los siete días. Acudió nuevamente con tumefacción blanda y difusa de ambas hemicaras, irritabilidad y fiebre. Se interconsultó con cirugía maxilofacial, se indicaron estudios sanguíneos y radiológicos. Se diagnosticó como enfermedad de Caffey, basado en la edad del niño, tumefacción facial sin signos inflamatorios agudos e hiperostosis en ambas corticales mandibulares a la radiografía AP mandíbula; unido a anemia ligera, leucocitosis y eritrosedimentación acelerada. El paciente se trató sintomáticamente y con antinflamatorios no esteroideos. Esta rara entidad se debe tener presente en casos de niños y lactantes con irritabilidad y fiebre inespecífica

  7. SHORT COMMUNICATION PROXIMATE COMPOSITION, MINERAL ...

    African Journals Online (AJOL)

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    SHORT COMMUNICATION. PROXIMATE COMPOSITION, MINERAL CONTENT AND ANTINUTRITIONAL. FACTORS OF SOME CAPSICUM (Capsicum annum) VARIETIES GROWN IN. ETHIOPIA. Esayas K.1, Shimelis A.2, Ashebir F.3, Negussie R.3, Tilahun B.4 and Gulelat D.4*. 1Hawassa University, Department of Food ...

  8. Comparative Analysis of Cortical Microinfarcts and Microbleeds using 3.0-Tesla Postmortem Magnetic Resonance Images and Histopathology.

    Science.gov (United States)

    Niwa, Atsushi; Ii, Yuichiro; Shindo, Akihiro; Matsuo, Ko; Ishikawa, Hidehiro; Taniguchi, Akira; Takase, Shinichi; Maeda, Masayuki; Sakuma, Hajime; Akatsu, Hiroyasu; Hashizume, Yoshio; Tomimoto, Hidekazu

    2017-01-01

    Microvascular lesions including cortical microinfarctions (CMIs) and cerebral lobar microbleeds (CMBs) are usually caused by cerebral amyloid angiopathy (CAA) in the elderly and are correlated with cognitive decline. However, their radiological-histopathological coincidence has not been revealed systematically with widely used 3-Tesla (3T) magnetic resonance imaging (MRI). The purpose of the present study is to delineate the histopathological background corresponding to MR images of these lesions. We examined formalin-fixed 10-mm thick coronal brain blocks from 10 CAA patients (five were also diagnosed with Alzheimer's disease, three with dementia with Lewy bodies, and two with CAA only) with dementia and six non CAA patients with neurodegenerative disease. Using 3T MRI, both 3D-fluid attenuated inversion recovery (FLAIR) and 3D-double inversion recovery (DIR) were examined to identify CMIs, and T2* and susceptibility-weighted images (SWI) were examined to identify CMBs. These blocks were subsequently examined histologically and immunohistochemically. In CAA patients, 48 CMIs and 6 lobar CMBs were invariably observed in close proximity to degenerated Aβ-positive blood vessels. Moreover, 16 CMIs (33%) of 48 were detected with postmortem MRI, but none were seen when the lesion size was smaller than 1 mm. In contrast, only 1 undeniable CMI was founded with MRI and histopathology in 6 non CAA patients. Small, cortical high-intensity lesions seen on 3D-FLAIR and 3D-DIR images likely represent CMIs, and low-intensity lesions in T2* and SWI correspond to CMBs with in vivo MRI. Furthermore, a close association between amyloid-laden vessels and these microvascular lesions indicated the contribution of CAA to their pathogenesis.

  9. The Unique Brain Anatomy of Meditation Practitioners: Alterations in Cortical Gyrification

    Directory of Open Access Journals (Sweden)

    Eileen eLuders

    2012-02-01

    Full Text Available Several cortical regions are reported to vary in meditation practitioners. However, since prior analyses were focused on examining gray matter or cortical thickness, additional effects with respect to other cortical features might have remained undetected. Gyrification (the pattern and degree of cortical folding is an important cerebral characteristic related to the geometry of the brain’s surface. Cortical folding occurs early in development and might be linked to behavioral traits. Thus, exploring cortical gyrification in long-term meditators may provide additional clues with respect to the underlying anatomical correlates of meditation. This study examined cortical gyrification in a large sample (n=100 of meditators and controls, carefully matched for sex and age. Cortical gyrification was established via calculating mean curvature across thousands of vertices on individual cortical surface models. Pronounced group differences indicating larger gyrification in meditators were evident within the left precentral gyrus, right fusiform gyrus, right cuneus, as well as left and right anterior dorsal insula (the latter representing the global significance maximum. Although the exact functional implications of larger cortical gyrification remain to be established, these findings suggest the insula to be a key structure involved in aspects of meditation. For example, variations in insular complexity could affect the regulation of well-known distractions in the process of meditation, such as daydreaming, mind-wandering, and projections into past or future. Moreover, given that meditators are masters in introspection, awareness, and emotional control, increased insular gyrification may reflect an ideal integration of autonomic, affective, and cognitive processes. Due to the cross-sectional nature of this study, further research is necessary determine the relative contribution of nature and nurture to links between cortical gyrification and meditation.

  10. Cortical Morphology Characteristics of Young Offspring of Patients With Schizophrenia or Bipolar Disorder.

    Science.gov (United States)

    Sugranyes, Gisela; Solé-Padullés, Cristina; de la Serna, Elena; Borras, Roger; Romero, Soledad; Sanchez-Gistau, Vanessa; Garcia-Rizo, Clemente; Goikolea, Jose Manuel; Bargallo, Nuria; Moreno, Dolores; Baeza, Inmaculada; Castro-Fornieles, Josefina

    2017-01-01

    Cortical surface area and thickness abnormalities have been observed in patients with schizophrenia and bipolar disorders; however, no study thus far has examined cortical morphologic measurements in children and adolescents at genetic risk for the disorders comparatively. One hundred thirty-seven participants, including 36 offspring of patients with schizophrenia (SzO), 54 offspring of patients with bipolar disorder (BpO), and 47 offspring of community controls (CcO), 6 to 17 years old, were assessed with clinical and neuroimaging methods. Sixty-nine percent of the sample was reassessed at a 27.6-month (mean) follow-up. Cortical surface reconstruction was applied to measure cortical area and thickness using FreeSurfer; mixed-effects models were used to investigate cross-sectional and longitudinal differences in global and lobar morphologic measurements. The SzO group exhibited a cross-sectional decrease in global, parietal, and occipital lobe surface area compared with the CcO group, and in the occipital lobe compared with the BpO group. In the SzO group, global and parietal surface area values were inversely associated with attenuated positive and negative prodromal symptom scores. No cross-sectional differences in cortical thickness were observed. Division of the sample by pubertal status showed group-by-time interactions in the pubertal and postpubertal SzO subgroup, with less longitudinal decrease in cortical surface area and thickness than in the CcO and BpO subgroups, respectively. The SzO, but not the BpO, group was characterized by cross-sectional decreases in surface area, and this was associated with prodromal symptoms. Longitudinal changes in cortical morphology associated with risk for schizophrenia may be expressed differently according to developmental stage. Copyright © 2016 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

  11. Effect of Probenecid on Tetraethyl Ammonium (TEA) Transport Across Basolateral Membrane of Rabbit Proximal Tubule

    Science.gov (United States)

    Choi, Tae Lyong; Kim, Yong Keun

    1992-01-01

    The effect of probenecid on the transport of tetraethylammonium (TEA) was investigated in rabbit reanal cortical slices in an attempt to ascertain the interaction of organic anion with the organic cation transport system in proximal tubule. Probenecid reversibly inhibited TEA uptake by cortical slices in a dose-dependent manner over the concentration range of 1 and 5 mM. The efflux of TEA was not affected by the presence of 3 mM probenecid. Kinetic analysis indicated that probenecid decreased Vmax without a significant change in Km. Probenecid inhibited significantly tissue oxgen consumption at concentrations of 3 and 5 mM. However, probenecid did not significantly reduce TEA uptake in brush border and basolateral membrane vesicles prepared from renal cortex even at higher concentration of 10 mM. These results indicate that probenecid reduces TEA uptake in cortical slices by inhibiting the tissue metabolism rather than by the interaction with the organic cation transporter. PMID:1306074

  12. Dynamic photophysical processes in laser irradiated human cortical skull bone

    Science.gov (United States)

    Mandelis, Andreas; Kwan, Chi-Hang; Matvienko, Anna

    2009-02-01

    Modulated luminescence (LUM) technique was applied to analyze photophysical processes in the cortical layer of human skull bones. The theoretical interpretation of the results was based on the optical excitation and decay rate equations of the fluorophore and on the molecular interaction parameter with the photon field density in the matrix of the bone. Using comparisons of the theory with the frequency response of dental LUM it was concluded that the optically active molecular species (fluorophore) in the bones is hydroxyapatite. An effective relaxation lifetime of skull cortical bone was derived theoretically and was found to depend on the intrinsic fluorophore decay lifetime, on the photon field density, and on the thickness of the bone. The experimentally measured dependencies were in excellent agreement with the theoretical model. The theory was able to yield measurements of the optical scattering coefficient, optical absorption coefficient, and mean coupling coefficient. These results show that the quantitative LUM can be used as a sensitive method to measure optical properties of the active fluorophore in cortical skull bones and the optical-field-induced molecular interaction parameter. When calibrated vs. laser intensity, the modulated luminescence can also be used to measure human skull thickness. These traits can be applied to monitor the bone mineral density (BMD) and, ultimately can be used as potential markers of bone health or disease, such as osteoporosis or bone cancer.

  13. Discriminant analysis of multiple cortical changes in mild cognitive impairment

    Science.gov (United States)

    Wu, Congling; Guo, Shengwen; Lai, Chunren; Wu, Yupeng; Zhao, Di; Jiang, Xingjun

    2017-02-01

    To reveal the differences in brain structures and morphological changes between the mild cognitive impairment (MCI) and the normal control (NC), analyze and predict the risk of MCI conversion. First, the baseline and 2-year longitudinal follow-up magnetic resonance (MR) images of 73 NC, 46 patients with stable MCI (sMCI) and 40 patients with converted MCI (cMCI) were selected. Second, the FreeSurfer was used to extract the cortical features, including the cortical thickness, surface area, gray matter volume and mean curvature. Third, the support vector machine-recursive feature elimination method (SVM-RFE) were adopted to determine salient features for effective discrimination. Finally, the distribution and importance of essential brain regions were described. The experimental results showed that the cortical thickness and gray matter volume exhibited prominent capability in discrimination, and surface area and mean curvature behaved relatively weak. Furthermore, the combination of different morphological features, especially the baseline combined with the longitudinal changes, can be used to evidently improve the performance of classification. In addition, brain regions with high weights predominately located in the temporal lobe and the frontal lobe, which were relative to emotional control and memory functions. It suggests that there were significant different patterns in the brain structure and changes between the compared group, which could not only be effectively applied for classification, but also be used to evaluate and predict the conversion of the patients with MCI.

  14. Cortical Correlates of Fitts’ Law

    Directory of Open Access Journals (Sweden)

    Peter eIfft

    2011-12-01

    Full Text Available Fitts' law describes the fundamental trade-off between movement accuracy and speed: It states that the duration of reaching movements is a function of target size and distance. While Fitts' law has been extensively studied in ergonomics and has guided the design of human-computer interfaces, there have been few studies on its neuronal correlates. To elucidate sensorimotor cortical activity underlying Fitts’ law, we implanted two monkeys with multielectrode arrays in the primary motor (M1 and primary somatosensory (S1 cortices. The monkeys performed reaches with a joystick-controlled cursor towards targets of different size. The reaction time, movement time and movement velocity changed with target size, and M1 and S1 activity reflected these changes. Moreover, modifications of cortical activity could not be explained by changes of movement parameters alone, but required target size as an additional parameter. Neuronal representation of target size was especially prominent during the early reaction time period where it influenced the slope of the firing rate rise preceding movement initiation. During the movement period, cortical activity was mostly correlated with movement velocity. Neural decoders were applied to simultaneously decode target size and motor parameters from cortical modulations. We suggest using such classifiers to improve neuroprosthetic control.

  15. Testosterone-Related Cortical Maturation Across Childhood and Adolescence

    Science.gov (United States)

    Nguyen, Tuong-Vi; McCracken, James; Ducharme, Simon; Botteron, Kelly N.; Mahabir, Megan; Johnson, Wendy; Israel, Mimi; Evans, Alan C.; Karama, Sherif

    2013-01-01

    Neuroendocrine theories of brain development hold testosterone as the predominant factor mediating sex-specific cortical growth and the ensuing lateralization of hemispheric function. However, studies to date have focussed on prenatal testosterone rather than pubertal changes in testosterone. Yet, animal studies have shown a high density of androgen-sensitive receptors in multiple key cortical areas, and puberty is known to coincide with both a significant rise in testosterone and the emergence of behavioral sex differences, suggesting peripubertal influences of testosterone on brain development. Here, we used linear mixed models to examine sex-specific cortical maturation associated with changes in testosterone levels in a longitudinal sample of developmentally healthy children and adolescents. A significant “sex by age by testosterone” interaction on cortical thickness (CTh) involving widespread areas of the developing brain was found. Testosterone levels were associated with CTh changes in regions of the left hemisphere in males and of the right hemisphere in females. In both sexes, the relationship between testosterone and CTh varied across the age span. These findings show the association between testosterone and CTh to be complex, highly dynamic, and to vary, depending on sex and age; they also suggest sex-related hemispheric lateralization effects of testosterone in humans. PMID:22617851

  16. Avaliação da espessura do esmalte proximal em segundos pré-molares superiores humanos e sua correlação com o diâmetro mésio-distal = Thickness valuation of adjacent enamel in second superior human pre molar teeth an their relationship with mesio distal diameter

    Directory of Open Access Journals (Sweden)

    Fischer, Luís Henrique

    2006-01-01

    Full Text Available A determinação da espessura do esmalte proximal à altura do ponto de contato é de grande importância, visto que o desgaste desta região dental é freqüentemente utilizado na clínica ortodôntica com a finalidade de correção de discrepâncias dentais e estabilidade do tratamento. Com o intuito de determinar os valores do diâmetro mésio-distal e aferir os valores médios da espessura do esmalte nas faces proximais à altura do ponto de contato, foram avaliados 42 segundos pré-molares superiores. Os diâmetros mésio-distais foram mensurados com auxílio de um paquímetro digital, em seguida foram incluídos em resina e seccionados obtendo-se uma lâmina central de 0,7 mm de espessura, possibilitando a medição da espessura do esmalte em um perfilômetro de precisão milesimal. Com base nos dados obtidos, também foram analisadas as possíveis correlações entre a espessura do esmalte nas faces proximais e o diâmetro mésio-distal. Os resultados indicaram que o valor médio do diâmetro mésio-distal é de 6,85 mm para o segundo pré-molar superior e com espessura media do esmalte de 1,101 mm na mesial e 1,157 mm na distal. De acordo com os testes de Spearman e Pearson foram encontradas correlações estatisticamente significantes no lado direito entre a espessura do esmalte na face mesial e o diâmetro mésio-distal, entre a espessura na face distal e o diâmetro mésiodistal. No lado esquerdo foram encontradas correlações positivas entre a espessura do esmalte distal e o diâmetro mésio-distal. Em ambos os lados houve correlações estatisticamente significantes entre a espessura do esmalte mesial e a espessura do esmalte distal. Independente do lado, a espessura média do esmalte é maior na face distal que na mesial

  17. Photoactivated In Vivo Proximity Labeling.

    Science.gov (United States)

    Beck, David B; Bonasio, Roberto

    2017-06-19

    Identification of molecular interactions is paramount to understanding how cells function. Most available technologies rely on co-purification of a protein of interest and its binding partners. Therefore, they are limited in their ability to detect low-affinity interactions and cannot be applied to proteins that localize to difficult-to-solubilize cellular compartments. In vivo proximity labeling (IPL) overcomes these obstacles by covalently tagging proteins and RNAs based on their proximity in vivo to a protein of interest. In IPL, a heterobifunctional probe comprising a photoactivatable moiety and biotin is recruited by a monomeric streptavidin tag fused to a protein of interest. Following UV irradiation, candidate interacting proteins and RNAs are covalently biotinylated with tight spatial and temporal control and subsequently recovered using biotin as an affinity handle. Here, we describe experimental protocols to discover novel protein-protein and protein-RNA interactions using IPL. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  18. Prox-1 Automated Proximity Operations

    Science.gov (United States)

    2016-01-13

    on demonstrating the functionality required to meet minimum mission success criteria. The minimum mission includes on- orbit spacecraft checkout of...also includes deployment of LightSail-B from the P-POD, and imaging of LightSail-B for 20 minutes as it recedes from Prox-1. small satellite ; proximity...criteria. The minimum mission includes on- orbit spacecraft checkout of all spacecraft subsystems, including flight qualification of the following new

  19. Development of Cortical Morphology Evaluated with Longitudinal MR Brain Images of Preterm Infants.

    Directory of Open Access Journals (Sweden)

    Pim Moeskops

    Full Text Available The cerebral cortex develops rapidly in the last trimester of pregnancy. In preterm infants, brain development is very vulnerable because of their often complicated extra-uterine conditions. The aim of this study was to quantitatively describe cortical development in a cohort of 85 preterm infants with and without brain injury imaged at 30 and 40 weeks postmenstrual age (PMA.In the acquired T2-weighted MR images, unmyelinated white matter (UWM, cortical grey matter (CoGM, and cerebrospinal fluid in the extracerebral space (CSF were automatically segmented. Based on these segmentations, cortical descriptors evaluating volume, surface area, thickness, gyrification index, and global mean curvature were computed at both time points, for the whole brain, as well as for the frontal, temporal, parietal, and occipital lobes separately. Additionally, visual scoring of brain abnormality was performed using a conventional scoring system at 40 weeks PMA.The evaluated descriptors showed larger change in the occipital lobes than in the other lobes. Moreover, the cortical descriptors showed an association with the abnormality scores: gyrification index and global mean curvature decreased, whereas, interestingly, median cortical thickness increased with increasing abnormality score. This was more pronounced at 40 weeks PMA than at 30 weeks PMA, suggesting that the period between 30 and 40 weeks PMA might provide a window of opportunity for intervention to prevent delay in cortical development.

  20. Reduced cortical complexity in children with Prader-Willi Syndrome and its association with cognitive impairment and developmental delay.

    Directory of Open Access Journals (Sweden)

    Akvile Lukoshe

    Full Text Available BACKGROUND: Prader-Willi Syndrome (PWS is a complex neurogenetic disorder with symptoms involving not only hypothalamic, but also a global, central nervous system dysfunction. Previously, qualitative studies reported polymicrogyria in adults with PWS. However, there have been no quantitative neuroimaging studies of cortical morphology in PWS and no studies to date in children with PWS. Thus, our aim was to investigate and quantify cortical complexity in children with PWS compared to healthy controls. In addition, we investigated differences between genetic subtypes of PWS and the relationship between cortical complexity and intelligence within the PWS group. METHODS: High-resolution structural magnetic resonance images were acquired in 24 children with genetically confirmed PWS (12 carrying a deletion (DEL, 12 with maternal uniparental disomy (mUPD and 11 age- and sex-matched typically developing siblings as healthy controls. Local gyrification index (lGI was obtained using the FreeSurfer software suite. RESULTS: Four large clusters, two in each hemisphere, comprising frontal, parietal and temporal lobes, had lower lGI in children with PWS, compared to healthy controls. Clusters with lower lGI also had significantly lower cortical surface area in children with PWS. No differences in cortical thickness of the clusters were found between the PWS and healthy controls. lGI correlated significantly with cortical surface area, but not with cortical thickness. Within the PWS group, lGI in both hemispheres correlated with Total IQ and Verbal IQ, but not with Performance IQ. Children with mUPD, compared to children with DEL, had two small clusters with lower lGI in the right hemisphere. lGI of these clusters correlated with cortical surface area, but not with cortical thickness or IQ. CONCLUSIONS: These results suggest that lower cortical complexity in children with PWS partially underlies cognitive impairment and developmental delay, probably due to

  1. Cortical morphology of the pars opercularis and its relationship to motor-inhibitory performance in a longitudinal, developing cohort.

    Science.gov (United States)

    Curley, Lauren B; Newman, Erik; Thompson, Wesley K; Brown, Timothy T; Hagler, Donald J; Akshoomoff, Natacha; Reuter, Chase; Dale, Anders M; Jernigan, Terry L

    2017-07-29

    This study investigates the relationship between variability in cortical surface area and thickness of the pars opercularis of the inferior frontal gyrus and motor-inhibitory performance on a stop-signal task in a longitudinal, typically developing cohort of children and adolescents. Linear mixed-effects models were used to investigate the hypotheses that (1) cortical thinning and (2) a relatively larger cortical surface area of the bilateral pars opercularis of the inferior frontal gyrus would predict better performance on the stop-signal task in a cohort of 110 children and adolescents 4-13 years of age, with one to four observations (totaling 232 observations). Cortical thickness of the bilateral opercular region was not related to inhibitory performance. However, independent of age, gender, and total cortical surface area, relatively larger cortical surface area of the bilateral opercular region of the inferior frontal gyrus was associated with better motor-inhibitory performance. Follow-up analyses showed a significant effect of surface area of the right pars opercularis, but no evidence for an effect of area of left pars opercularis, on motor-inhibitory performance. These findings are consistent with the previous work in adults showing that cortical morphology of the pars opercularis is related to inhibitory functioning. It also expands upon this literature by showing that, in contrast to earlier work highlighting the importance of cortical thickness of this region in adults, relative cortical surface area of the pars opercularis may be related to developing motor-inhibitory functions during childhood and adolescence. Relationships between cortical phenotypes and individual differences in behavioral measures may vary across the lifespan.

  2. Right temporal cortical hypertrophy in resilience to trauma: an MRI study

    Directory of Open Access Journals (Sweden)

    André Sevenius Nilsen

    2016-07-01

    Full Text Available Background: In studies employing physiological measures such as magnetic resonance imaging (MRI, it is often hard to distinguish what constitutes risk-resilience factors to posttraumatic stress disorder (PTSD following trauma exposure and what the effects of trauma exposure and PTSD are. Objective: We aimed to investigate whether there were observable morphological differences in cortical and sub-cortical regions of the brain, 7–8 years after a single potentially traumatic event. Methods: Twenty-four participants, who all directly experienced the 2004 Indian Ocean Tsunami, and 25 controls, underwent structural MRI using a 3T scanner. We generated cortical thickness maps and parcellated sub-cortical volumes for analysis. Results: We observed greater cortical thickness for the trauma-exposed participants relative to controls, in a right lateralized temporal lobe region including anterior fusiform gyrus, and superior, middle, and inferior temporal gyrus. Conclusions: We observed greater thickness in the right temporal lobe which might indicate that the region could be implicated in resilience to the long-term effects of a traumatic event. We hypothesize this is due to altered emotional semantic memory processing. However, several methodological and confounding issues warrant caution in interpretation of the results.

  3. Paroxysmal kinesigenic dyskinesia : Cortical or non-cortical origin

    NARCIS (Netherlands)

    van Strien, Teun W.; van Rootselaar, Anne-Fleur; Hilgevoord, Anthony A. J.; Linssen, Wim H. J. P.; Groffen, Alexander J. A.; Tijssen, Marina A. J.

    Paroxysmal kinesigenic dyskinesia (PKD) is characterized by involuntary dystonia and/or chorea triggered by a sudden movement. Cases are usually familial with an autosomal dominant inheritance. Hypotheses regarding the pathogenesis of PKD focus on the controversy whether PKD has a cortical or

  4. Cortical atrophy patterns in multiple sclerosis are non-random and clinically relevant.

    Science.gov (United States)

    Steenwijk, Martijn D; Geurts, Jeroen J G; Daams, Marita; Tijms, Betty M; Wink, Alle Meije; Balk, Lisanne J; Tewarie, Prejaas K; Uitdehaag, Bernard M J; Barkhof, Frederik; Vrenken, Hugo; Pouwels, Petra J W

    2016-01-01

    Grey matter atrophy is common in multiple sclerosis. However, in contrast with other neurodegenerative diseases, it is unclear whether grey matter atrophy in multiple sclerosis is a diffuse 'global' process or develops, instead, according to distinct anatomical patterns. Using source-based morphometry we searched for anatomical patterns of co-varying cortical thickness and assessed their relationships with white matter pathology, physical disability and cognitive functioning. Magnetic resonance imaging was performed at 3 T in 208 patients with long-standing multiple sclerosis (141 females; age = 53.7 ± 9.6 years; disease duration = 20.2 ± 7.1 years) and 60 age- and sex-matched healthy controls. Spatial independent component analysis was performed on cortical thickness maps derived from 3D T1-weighted images across all subjects to identify co-varying patterns. The loadings, which reflect the presence of each cortical thickness pattern in a subject, were compared between patients with multiple sclerosis and healthy controls with generalized linear models. Stepwise linear regression analyses were used to assess whether white matter pathology was associated with these loadings and to identify the cortical thickness patterns that predict measures of physical and cognitive dysfunction. Ten cortical thickness patterns were identified, of which six had significantly lower loadings in patients with multiple sclerosis than in controls: the largest loading differences corresponded to the pattern predominantly involving the bilateral temporal pole and entorhinal cortex, and the pattern involving the bilateral posterior cingulate cortex. In patients with multiple sclerosis, overall white matter lesion load was negatively associated with the loadings of these two patterns. The final model for physical dysfunction as measured with Expanded Disability Status Scale score (adjusted R(2) = 0.297; P regression models, they explained limited incremental variance (to a maximum of 4

  5. PROXIMATE AND ELEMENTAL COMPOSITION OF WHITE GRUBS

    African Journals Online (AJOL)

    DR. AMINU

    PROXIMATE AND ELEMENTAL COMPOSITION OF WHITE GRUBS. 1 Alhassan, A. J. 1M .S. Sule, 1J. ... ABSTRACT. This study determined the proximate and mineral element composition of whole white grubs using standard methods of analysis. Proximate ... days, before pulverized to powder and kept in plastic container.

  6. Verbal memory impairments in schizophrenia associated with cortical thinning

    Directory of Open Access Journals (Sweden)

    S. Guimond

    2016-01-01

    Full Text Available Verbal memory (VM represents one of the most affected cognitive domains in schizophrenia. Multiple studies have shown that schizophrenia is associated with cortical abnormalities, but it remains unclear whether these are related to VM impairments. Considering the vast literature demonstrating the role of the frontal cortex, the parahippocampal cortex, and the hippocampus in VM, we examined the cortical thickness/volume of these regions. We used a categorical approach whereby 27 schizophrenia patients with ‘moderate to severe’ VM impairments were compared to 23 patients with ‘low to mild’ VM impairments and 23 healthy controls. A series of between-group vertex-wise GLM on cortical thickness were performed for specific regions of interest defining the parahippocampal gyrus and the frontal cortex. When compared to healthy controls, patients with ‘moderate to severe’ VM impairments revealed significantly thinner cortex in the left frontal lobe, and the parahippocampal gyri. When compared to patients with ‘low to mild’ VM impairments, patients with ‘moderate to severe’ VM impairments showed a trend of thinner cortex in similar regions. Virtually no differences were observed in the frontal area of patients with ‘low to mild’ VM impairments relative to controls. No significant group differences were observed in the hippocampus. Our results indicate that patients with greater VM impairments demonstrate significant cortical thinning in regions known to be important in VM performance. Treating VM deficits in schizophrenia could have a positive effect on the brain; thus, subgroups of patients with more severe VM deficits should be a prioritized target in the development of new cognitive treatments.

  7. Visualizing stages of cortical atrophy in progressive MCI from the ADNI cohort

    DEFF Research Database (Denmark)

    Eskildsen, Simon Fristed; Fonov, Vladimir; Coupé, Pierrick

    Amnestic mild cognitive impairment (MCI) is considered a condition where patients are at risk of developing clinically definite Alzheimer’s disease (AD) with an annual conversion rate of approximately 15%[1]. AD is characterized by progressive brain atrophy with major impact on the cerebral cortex...... and medial temporal lobe structures such as hippocampus. Understanding the structural pattern of cortical atrophy at different stages of MCI, before AD can be diagnosed, may help in patient monitoring and prognosis. We used data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) to calculate...... thickness were measured using FACE[6] and mapped to an average cortical surface. Statistical maps of differences in cortical thickness between groups of MCI patients and HC were constructed and corrected for multiple comparisons. Three years prior to clinically definite AD, the MCI patients show signs...

  8. Positive symptoms associate with cortical thinning in the superior temporal gyrus via the ENIGMA Schizophrenia consortium

    NARCIS (Netherlands)

    Walton, E.; Hibar, D. P.; van Erp, T. G M; Potkin, S. G.; Roiz-Santiañez, R.; Crespo-Facorro, B.; Suarez-Pinilla, P.; Van Haren, N. E M|info:eu-repo/dai/nl/271562161; de Zwarte, S. M C; Kahn, R. S.|info:eu-repo/dai/nl/073778532; Cahn, W.|info:eu-repo/dai/nl/250566370; Doan, N. T.; Jørgensen, K. N.; Gurholt, T. P.; Agartz, I.; Andreassen, O. A.; Westlye, L. T.; Melle, I.; Berg, A. O.; Mørch-Johnsen, L.; Færden, A.; Flyckt, L.; Fatouros-Bergman, H.; Jönsson, E. G.; Hashimoto, R.; Yamamori, H.; Fukunaga, M.; Preda, A.; De Rossi, P.; Piras, F.; Banaj, N.; Ciullo, V.; Spalletta, G.; Gur, R. E.; Gur, R. C.; Wolf, D. H.; Satterthwaite, T. D.; Beard, L. M.; Sommer, I. E.|info:eu-repo/dai/nl/258791519; Koops, S.; Gruber, O.; Richter, A.; Krämer, B.; Kelly, S.; Donohoe, G.; McDonald, C.; Cannon, D. M.; Corvin, A.; Gill, M.; Di Giorgio, A.; Bertolino, A.; Lawrie, S.; Nickson, T.; Whalley, H. C.; Neilson, E.; Calhoun, V. D.; Thompson, P. M.; Turner, J. A.; Ehrlich, S.; Farde, L.; Engberg, G.; Erhardt, S.; Fatouros-Bergman, H.; Cervenka, S.; Schwieler, L.; Piehl, F.; Ikonen, P.; Collste, K.; Orhan, F.; Malmqvist, A.; Hedberg, M.

    2017-01-01

    Objective: Based on the role of the superior temporal gyrus (STG) in auditory processing, language comprehension and self-monitoring, this study aimed to investigate the relationship between STG cortical thickness and positive symptom severity in schizophrenia. Method: This prospective meta-analysis

  9. Cortical deafness in multiple sclerosis

    OpenAIRE

    Tabira, T; Tsuji, S; Nagashima, T.; Nakajima, T.; Kuroiwa, Y

    1981-01-01

    Cortical deafness in a patient with multiple sclerosis is reported. Complete recovery from total deafness was seen following stages of auditory agnosia and pure word deafness. The otological and neurophysiological studies suggested lesions in subcortical white matter. This report stresses the rarity of the condition, its subcortical origin and good prognosis.

  10. Decreased cortical representation of genital somatosensory field after childhood sexual abuse.

    Science.gov (United States)

    Heim, Christine M; Mayberg, Helen S; Mletzko, Tanja; Nemeroff, Charles B; Pruessner, Jens C

    2013-06-01

    Sexual dysfunction is a common clinical symptom in women who were victims of childhood sexual abuse. The precise mechanism that mediates this association remains poorly understood. The authors evaluated the relationship between the experience of childhood abuse and neuroplastic thinning of cortical fields, depending on the nature of the abusive experience. The authors used MRI-based cortical thickness analysis in 51 medically healthy adult women to test whether different forms of childhood abuse were associated with cortical thinning in areas critical to the perception and processing of specific behavior implicated in the type of abuse. Exposure to childhood sexual abuse was specifically associated with pronounced cortical thinning in the genital representation field of the primary somatosensory cortex. In contrast, emotional abuse was associated with cortical thinning in regions relevant to self-awareness and self-evaluation. Neural plasticity during development appears to result in cortical adaptation that may shield a child from the sensory processing of the specific abusive experience by altering cortical representation fields in a regionally highly specific manner. Such plastic reorganization may be protective for the child living under abusive conditions, but it may underlie the development of behavioral problems, such as sexual dysfunction, later in life.

  11. Delays in thick targets

    CERN Document Server

    Bennett, J R J

    2002-01-01

    The delays in the emission of radioactive particles from a thick target bombarded by high-energy protons is discussed in relation to the basic physical processes of diffusion and effusion through the target and ioniser. The delay time, relative to the decay time, is crucial to the efficiency of particle release at the exit of the ioniser. The principles of minimizing the delay times are discussed with reference to a mathematical model of the process, and some experimental examples are given.

  12. Regional cortical thinning predicts worsening apathy and hallucinations across the Alzheimer disease spectrum.

    Science.gov (United States)

    Donovan, Nancy J; Wadsworth, Lauren P; Lorius, Natacha; Locascio, Joseph J; Rentz, Dorene M; Johnson, Keith A; Sperling, Reisa A; Marshall, Gad A

    2014-11-01

    To examine regions of cortical thinning and cerebrospinal fluid (CSF) Alzheimer disease (AD) biomarkers associated with apathy and hallucinations in a continuum of individuals including clinically normal elderly, mild cognitive impairment, and mild AD dementia. Cross-sectional and longitudinal studies. Fifty-seven research sites across North America. Eight-hundred twelve community-dwelling volunteers; 413 participants in the CSF sub-study. Structural magnetic resonance imaging data and CSF concentrations of amyloid-β 1-42, total tau, and phosphorylated tau derived from the Alzheimer Disease Neuroimaging Initiative database were analyzed. Apathy and hallucinations were measured at baseline and over 3 years using the Neuropsychiatric Inventory-Questionnaire. General linear models and mixed effects models were used to evaluate the relationships among baseline cortical thickness in seven regions, and baseline CSF biomarkers, apathy, and hallucinations at baseline and longitudinally. Covariates included diagnosis, sex, age, apolipoprotein E genotype, premorbid intelligence, memory performance, processing speed, antidepressant use, and AD duration. Reduced baseline inferior temporal cortical thickness was predictive of increasing apathy over time, and reduced supramarginal cortical thickness was predictive of increasing hallucinations over time. There was no association with cortical thickness at baseline. CSF biomarkers were not related to severity of apathy or hallucinations in cross-sectional or longitudinal analyses. These results suggest that greater baseline temporal and parietal atrophy is associated with worsening apathy and hallucinations in a large AD spectrum cohort, while adjusting for multiple disease-related variables. Localized cortical neurodegeneration may contribute to the pathophysiology of apathy and hallucinations and their adverse consequences in AD. Copyright © 2014 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All

  13. Anthropometric analysis of the human mandibular cortical bone as assessed by cone-beam computed tomography.

    Science.gov (United States)

    Swasty, Denise; Lee, Janice S; Huang, John C; Maki, Koutaro; Gansky, Stuart A; Hatcher, David; Miller, Arthur J

    2009-03-01

    The purpose of this study is to assess cortical thickness, height, and width with cone-beam computed tomography (CBCT), and determine the relationship of these parameters with age. A total of 113 subjects from the University of California at San Francisco Orthodontic Clinic with a CBCT scan were enrolled. Subjects were stratified by age in decades. Thickness of buccal and lingual cortices and mandibular height and width were evaluated in 5 regions (13 sites). A single factorial ANOVA was used to compare the parameters among age groups. P less than or equal to .05 was statistically significant. There were 44 (38.9%) males; 69 females. For all groups, the thickest to the least thick cortical plates were: base of the mandible, lower buccal one third, upper lingual one third, upper buccal one third, and lower lingual one third. In all groups, the mandible increased in height as the midline was approached, and the width of the upper third of the mandible decreased from the second molar to the symphysis whereas the reverse occurred in the lower third. Comparison of the age groups showed that subjects 10 to 19 years old had thinner cortical plates than other age groups (P mandibular height (P mandibular cortical bone is thickest at the base, on the buccal side. Subjects who are 10 to 19 years old have thinner cortical bone and decreased mandibular height compared with all other age groups. The mandible continues to mature through 40 to 49 years of age and then decreases in thickness after this period.

  14. Finger Proximal Interphalangeal Joint Dislocation.

    Science.gov (United States)

    Ramponi, Denise; Cerepani, Mary Jo

    2015-01-01

    Finger dislocations are common injuries that are often managed by emergency nurse practitioners. A systematic physical examination following these injuries is imperative to avoid complications. Radiographic views, including the anteroposterior, lateral, and oblique views, are imperative to evaluate these finger dislocations. A dorsal dislocation of the proximal interphalangeal (PIP) joint is the most common finger dislocation type often easily reduced. A volar PIP dislocation can often be difficult to reduce and may result in finger deformity. Finger dislocations should be reduced promptly. Referral to an orthopedic hand specialist is required if the dislocation is unable to be reduced or if the finger joint is unstable following reduction attempts.

  15. Equilibrium properties of proximity effect

    Energy Technology Data Exchange (ETDEWEB)

    Esteve, D.; Pothier, H.; Gueron, S.; Birge, N.O.; Devoret, M.

    1996-12-31

    The proximity effect in diffusive normal-superconducting (NS) nano-structures is described by the Usadel equations for the electron pair correlations. We show that these equations obey a variational principle with a potential which generalizes the Ginzburg-Landau energy functional. We discuss simple examples of NS circuits using this formalism. In order to test the theoretical predictions of the Usadel equations, we have measured the density of states as a function of energy on a long N wire in contact with a S wire at one end, at different distances from the NS interface. (authors). 12 refs.

  16. Thickness Distribution of Glenohumeral Joint Cartilage.

    Science.gov (United States)

    Schleich, Christoph; Bittersohl, Bernd; Antoch, Gerald; Krauspe, Rüdiger; Zilkens, Christoph; Kircher, Jörn

    2017-04-01

    High-resolution 3-dimensional cartilage-specific magnetic resonance imaging (MRI) was performed at 3 T to test the following hypotheses: (1) there is a nonuniform cartilage thickness distribution both on the proximal humerus and on the glenoid surface and (2) the glenohumeral joint as a combined system is congruent with the level of the joint cartilage surface without substantial radial mismatch. Inclusion of 38 volunteers (19 females, mean age 24.34 ± 2.22 years; range 21-29 years) in a prospective study. Measurements of: cartilage thickness in 3 regions and 3 zones; radius of both circles (glenoid and humeral cartilage) for congruency calculation using 3-T MRI with 3-dimensional dual-echo steady-state sequence with water excitation. A homogenous mean cartilage thickness (1.2-1.5 mm) and slightly higher values for the glenoidal articulating surface radii both in the mid-paracoronar section (2.4 vs. 2.1 cm, P cartilage changes at the shoulder for future studies.

  17. Variations in the buccal-lingual alveolar bone thickness of impacted mandibular third molar: our classification and treatment perspectives.

    Science.gov (United States)

    Ge, Jing; Zheng, Jia-Wei; Yang, Chi; Qian, Wen-Tao

    2016-01-13

    Selecting either buccal or lingual approach for the mandibular third molar surgical extraction has been an intense debate for years. The aim of this observational retrospective study was to classify the molar based on the proximity to the external cortical bone, and analyze the position of inferior alveolar canal (IAC) of each type. Cone-beam CT (CBCT) data of 110 deeply impacted mandibular third molars from 91 consecutive patients were analyzed. A new classification based on the mean deduction value (MD) of buccal-lingual alveolar bone thickness was proposed: MD≥1 mm was classified as buccal position, 1 mm>MD>-1 mm was classified as central position, MD≤-1 mm was classified as lingual position. The study samples were distributed as: buccal position (1.8%) in 2 subjects, central position (10.9%) in 12 and lingual position (87.3%) in 96. Ninety-six molars (87.3%) contacted the IAC. The buccal and inferior IAC course were the most common types in impacted third molar, especially in lingually positioned ones. Our study suggested that amongst deeply impacted mandibular third molars, lingual position occupies the largest proportion, followed by the central, and then the buccal type.

  18. Mnemonic Encoding and Cortical Organization in Parietal and Prefrontal Cortices.

    Science.gov (United States)

    Masse, Nicolas Y; Hodnefield, Jonathan M; Freedman, David J

    2017-06-21

    Persistent activity within the frontoparietal network is consistently observed during tasks that require working memory. However, the neural circuit mechanisms underlying persistent neuronal encoding within this network remain unresolved. Here, we ask how neural circuits support persistent activity by examining population recordings from posterior parietal (PPC) and prefrontal (PFC) cortices in two male monkeys that performed spatial and motion direction-based tasks that required working memory. While spatially selective persistent activity was observed in both areas, robust selective persistent activity for motion direction was only observed in PFC. Crucially, we find that this difference between mnemonic encoding in PPC and PFC is associated with the presence of functional clustering: PPC and PFC neurons up to ∼700 μm apart preferred similar spatial locations, and PFC neurons up to ∼700 μm apart preferred similar motion directions. In contrast, motion-direction tuning similarity between nearby PPC neurons was much weaker and decayed rapidly beyond ∼200 μm. We also observed a similar association between persistent activity and functional clustering in trained recurrent neural network models embedded with a columnar topology. These results suggest that functional clustering facilitates mnemonic encoding of sensory information. SIGNIFICANCE STATEMENT Working memory refers to our ability to temporarily store and manipulate information. Numerous studies have observed that, during working memory, neurons in higher cortical areas, such as the parietal and prefrontal cortices, mnemonically encode the remembered stimulus. However, several recent studies have failed to observe mnemonic encoding during working memory, raising the question as to why mnemonic encoding is observed during some, but not all, conditions. In this study, we show that mnemonic encoding occurs when a cortical area is organized such that nearby neurons preferentially respond to the same

  19. Distribution of bone density in the proximal femur and its association with hip fracture risk in older men: the osteoporotic fractures in men (MrOS) study.

    Science.gov (United States)

    Yang, Lang; Burton, Annabel C; Bradburn, Mike; Nielson, Carrie M; Orwoll, Eric S; Eastell, Richard

    2012-11-01

    This prospective case-cohort study aimed to map the distribution of bone density in the proximal femur and examine its association with hip fracture. We analyzed baseline quantitative computed tomography (QCT) scans in 250 men aged 65 years or older, which comprised a randomly-selected subcohort of 210 men and 40 cases of first hip fracture during a mean follow-up period of 5.5 years. We quantified cortical, trabecular, and integral volumetric bone mineral density (vBMD), and cortical thickness (CtTh) in four quadrants of cross-sections along the length of the femoral neck (FN), intertrochanter (IT), and trochanter (TR). In most quadrants, vBMDs and CtTh were significantly (p fracture, we merged the two quadrants in the medial and lateral aspects of the FN, IT, and TR. At most sites, QCT measurements were associated significantly (p fracture, the hazard ratio (HR) adjusted for age, body mass index (BMI), and clinical site for a 1-SD decrease ranged between 2.28 (95% confidence interval [CI], 1.44-3.63) to 6.91 (95% CI, 3.11-15.53). After additional adjustment for total hip (TH) areal BMD (aBMD), trabecular vBMDs at the FN, TR, and TH were still associated with hip fracture significantly (p fracture significantly (p > 0.05) better than TH aBMD. With an area under the receiver operating characteristic curve (AUC) of 0.901 (95% CI, 0.852-0.950), the regression model combining TH aBMD, age, and trabecular vBMD predicted hip fracture significantly (p fracture risk and highlight trabecular vBMD at the FN and TR as an independent risk factor. Copyright © 2012 American Society for Bone and Mineral Research.

  20. Are women with thicker cortices in the femoral shaft at higher risk of subtrochanteric/diaphyseal fractures? The study of osteoporotic fractures.

    Science.gov (United States)

    Napoli, Nicola; Jin, Jenny; Peters, Katherine; Wustrack, Rosanna; Burch, Shane; Chau, Aldric; Cauley, Jane; Ensrud, Kristine; Kelly, Michael; Black, Dennis M

    2012-07-01

    Femoral shaft cortical thickening has been mentioned in reports of atypical subtrochanteric and diaphyseal (S/D) femur fractures, but it is unclear whether thickening precedes fracture or results from a preceding stress fracture and what role bisphosphonates might play in cortical thickening. Our objective was to examine the relationship of cortical thickness to S/D fracture risk as well as establish normal reference values for femoral cortical thickness in a large population-based cohort of older women. Using pelvic radiographs obtained in 1986-1988, we measured femoral shaft cortical thickness 3 cm below the lesser trochanter in women in the Study of Osteoporotic Fractures. We measured this in a random sample and in those with S/D fractures and femoral neck and intertrochanteric fractures. Low-energy S/D fractures were identified from review of radiographic reports obtained between 1986 and 2010. Radiographs to evaluate atypia were not available. Analysis used case-cohort, proportional hazards models. Cortical thickness as a risk factor for low-energy S/D femur fractures as well as femoral neck and intertrochanteric fractures in the Study of Osteoporotic Fractures, adjusting for age and bone mineral density in proportional hazards models. After age adjustment, women with thinner medial cortices were at a higher risk of S/D femur fracture, with a relative hazard of 3.94 (95% confidence interval = 1.23-12.6) in the lowest vs. highest quartile. Similar hazard ratios were seen for femoral neck and intertrochanteric fractures. Medial or total cortical thickness was more strongly related to fracture risk than lateral cortical thickness. In primarily bisphosphonate-naive women, we found no evidence that thick femoral cortices placed women at higher risk for low-energy S/D femur fractures; in fact, the opposite was true. Women with thin cortices were also at a higher risk for femoral neck and intertrochanteric fractures. Whether cortical thickness among bisphosphonate

  1. Changes in thickness and surface area of the human cortex and their relationship with intelligence.

    Science.gov (United States)

    Schnack, Hugo G; van Haren, Neeltje E M; Brouwer, Rachel M; Evans, Alan; Durston, Sarah; Boomsma, Dorret I; Kahn, René S; Hulshoff Pol, Hilleke E

    2015-06-01

    Changes in cortical thickness over time have been related to intelligence, but whether changes in cortical surface area are related to general cognitive functioning is unknown. We therefore examined the relationship between intelligence quotient (IQ) and changes in cortical thickness and surface over time in 504 healthy subjects. At 10 years of age, more intelligent children have a slightly thinner cortex than children with a lower IQ. This relationship becomes more pronounced with increasing age: with higher IQ, a faster thinning of the cortex is found over time. In the more intelligent young adults, this relationship reverses so that by the age of 42 a thicker cortex is associated with higher intelligence. In contrast, cortical surface is larger in more intelligent children at the age of 10. The cortical surface is still expanding, reaching its maximum area during adolescence. With higher IQ, cortical expansion is completed at a younger age; and once completed, surface area decreases at a higher rate. These findings suggest that intelligence may be more related to the magnitude and timing of changes in brain structure during development than to brain structure per se, and that the cortex is never completed but shows continuing intelligence-dependent development. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Growth hormone effects on cortical bone dimensions in young adults with childhood-onset growth hormone deficiency

    DEFF Research Database (Denmark)

    Hyldstrup, L; Conway, G S; Racz, K

    2012-01-01

    Growth hormone (GH) treatment in young adults with childhood-onset GH deficiency has beneficial effects on bone mass. The present study shows that cortical bone dimensions also benefit from GH treatment, with endosteal expansion and increased cortical thickness leading to improved bone strength....... INTRODUCTION: In young adults with childhood-onset growth hormone deficiency (CO GHD), GH treatment after final height is reached has been shown to have beneficial effects on spine and hip bone mineral density. The objective of the study was to evaluate the influence of GH on cortical bone dimensions. METHODS...

  3. Imprinting and recalling cortical ensembles.

    Science.gov (United States)

    Carrillo-Reid, Luis; Yang, Weijian; Bando, Yuki; Peterka, Darcy S; Yuste, Rafael

    2016-08-12

    Neuronal ensembles are coactive groups of neurons that may represent building blocks of cortical circuits. These ensembles could be formed by Hebbian plasticity, whereby synapses between coactive neurons are strengthened. Here we report that repetitive activation with two-photon optogenetics of neuronal populations from ensembles in the visual cortex of awake mice builds neuronal ensembles that recur spontaneously after being imprinted and do not disrupt preexisting ones. Moreover, imprinted ensembles can be recalled by single- cell stimulation and remain coactive on consecutive days. Our results demonstrate the persistent reconfiguration of cortical circuits by two-photon optogenetics into neuronal ensembles that can perform pattern completion. Copyright © 2016, American Association for the Advancement of Science.

  4. Best focus shift mechanism for thick masks

    Science.gov (United States)

    Burkhardt, Martin; Raghunathan, Ananthan

    2015-03-01

    The best focus shift due to thick mask effects is well known, both in ArF, and more importantly in EUV, where the shorter wavelength is small compared to both mask openings and absorber height. While the effect is stronger in opaque features in clear field masks, the best focus shift is visible in dark field masks as well, and it becomes even more pronounced when scattering bars are added to non-dense features. This pattern dependent focus variation can be predicted in both exact EMF simulations and fast image calculations that are used for optical proximity correction (OPC). Even though this focus shift can be predicted and patterns can be corrected in OPC, we would like to understand the mechanism that causes this focus shift. This can help us understand if, in addition to best focus shift, the image quality is further deteriorated due to the thick mask effects. The best focus shift is found to be an interplay of the complex diffraction coefficient due to thick mask effects and the direction of the light that is incident on the mask, or coherence value σ. A change in focus adds a phase term to each of the complex diffraction coefficients, causing their rotation in a phasor diagram. Best focus is found when the phasors have an angle of 0 or 180 degrees to each other and depending on which diffracted orders are caught in the pupil and contribute to imaging. We investigate the effect of partial coherence, mask thickness, and assist feature placement on best focus shift. We observe a waveguide effect in the absorber gaps because of the reduced real index of refraction in the absorber layer, making vacuum the optically dense medium. We suggest ways to lessen the best focus shifts through assist feature placement or the use of alternative absorbers that are closer matched to the dielectric index of vacuum.

  5. Detection and quantification of regional cortical gray matter damage in multiple sclerosis utilizing gradient echo MRI

    Directory of Open Access Journals (Sweden)

    Jie Wen

    2015-01-01

    Full Text Available Cortical gray matter (GM damage is now widely recognized in multiple sclerosis (MS. The standard MRI does not reliably detect cortical GM lesions, although cortical volume loss can be measured. In this study, we demonstrate that the gradient echo MRI can reliably and quantitatively assess cortical GM damage in MS patients using standard clinical scanners. High resolution multi-gradient echo MRI was used for regional mapping of tissue-specific MRI signal transverse relaxation rate values (R2* in 10 each relapsing–remitting, primary-progressive and secondary-progressive MS subjects. A voxel spread function method was used to correct artifacts induced by background field gradients. R2* values from healthy controls (HCs of varying ages were obtained to establish baseline data and calculate ΔR2* values – age-adjusted differences between MS patients and HC. Thickness of cortical regions was also measured in all subjects. In cortical regions, ΔR2* values of MS patients were also adjusted for changes in cortical thickness. Symbol digit modalities (SDMT and paced auditory serial addition (PASAT neurocognitive tests, as well as Expanded Disability Status Score, 25-foot timed walk and nine-hole peg test results were also obtained on all MS subjects. We found that ΔR2* values were lower in multiple cortical GM and normal appearing white matter (NAWM regions in MS compared with HC. ΔR2* values of global cortical GM and several specific cortical regions showed significant (p < 0.05 correlations with SDMT and PASAT scores, and showed better correlations than volumetric measures of the same regions. Neurological tests not focused on cognition (Expanded Disability Status Score, 25-foot timed walk and nine-hole peg tests showed no correlation with cortical GM ΔR2* values. The technique presented here is robust and reproducible. It requires less than 10 min and can be implemented on any MRI scanner. Our results show that quantitative tissue-specific R2

  6. Complications in proximal humeral fractures.

    Science.gov (United States)

    Calori, Giorgio Maria; Colombo, Massimiliano; Bucci, Miguel Simon; Fadigati, Piero; Colombo, Alessandra Ines Maria; Mazzola, Simone; Cefalo, Vittorio; Mazza, Emilio

    2016-10-01

    Necrosis of the humeral head, infections and non-unions are among the most dangerous and difficult-to-treat complications of proximal humeral fractures. The aim of this work was to analyse in detail non-unions and post-traumatic bone defects and to suggest an algorithm of care. Treatment options are based not only on the radiological frame, but also according to a detailed analysis of the patient, who is classified using a risk factor analysis. This method enables the surgeon to choose the most suitable treatment for the patient, thereby facilitating return of function in the shortest possible time. The treatment of such serious complications requires the surgeon to be knowledgeable about the following possible solutions: increased mechanical stability; biological stimulation; and reconstructive techniques in two steps, with application of biotechnologies and prosthetic substitution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Progressive Brain Atrophy and Cortical Thinning in Schizophrenia after Commencing Clozapine Treatment

    Science.gov (United States)

    Ahmed, Mohamed; Cannon, Dara M; Scanlon, Cathy; Holleran, Laurena; Schmidt, Heike; McFarland, John; Langan, Camilla; McCarthy, Peter; Barker, Gareth J; Hallahan, Brian; McDonald, Colm

    2015-01-01

    Despite evidence that clozapine may be neuroprotective, there are few longitudinal magnetic resonance imaging (MRI) studies that have specifically explored an association between commencement of clozapine treatment for schizophrenia and changes in regional brain volume or cortical thickness. A total of 33 patients with treatment-resistant schizophrenia and 31 healthy controls matched for age and gender underwent structural MRI brain scans at baseline and 6–9 months after commencing clozapine. MRI images were analyzed using SIENA (Structural Image Evaluation, using Normalization, of Atrophy) and FreeSurfer to investigate changes over time in brain volume and cortical thickness respectively. Significantly greater reductions in volume were detected in the right and left medial prefrontal cortex and in the periventricular area in the patient group regardless of treatment response. Widespread further cortical thinning was observed in patients compared with healthy controls. The majority of patients improved symptomatically and functionally over the study period, and patients who improved were more likely to have less cortical thinning of the left medial frontal cortex and the right middle temporal cortex. These findings demonstrate on-going reductions in brain volume and progressive cortical thinning in patients with schizophrenia who are switched to clozapine treatment. It is possible that this gray matter loss reflects a progressive disease process irrespective of medication use or that it is contributed to by switching to clozapine treatment. The clinical improvement of most patients indicates that antipsychotic-related gray matter volume loss may not necessarily be harmful or reflect neurotoxicity. PMID:25829144

  8. In vivo high-resolution 7 Tesla MRI shows early and diffuse cortical alterations in CADASIL.

    Science.gov (United States)

    De Guio, François; Reyes, Sonia; Vignaud, Alexandre; Duering, Marco; Ropele, Stefan; Duchesnay, Edouard; Chabriat, Hugues; Jouvent, Eric

    2014-01-01

    Recent data suggest that early symptoms may be related to cortex alterations in CADASIL (Cerebral Autosomal-Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy), a monogenic model of cerebral small vessel disease (SVD). The aim of this study was to investigate cortical alterations using both high-resolution T2* acquisitions obtained with 7 Tesla MRI and structural T1 images with 3 Tesla MRI in CADASIL patients with no or only mild symptomatology (modified Rankin's scale ≤1 and Mini Mental State Examination (MMSE) ≥24). Complete reconstructions of the cortex using 7 Tesla T2* acquisitions with 0.7 mm isotropic resolution were obtained in 11 patients (52.1±13.2 years, 36% male) and 24 controls (54.8±11.0 years, 42% male). Seven Tesla T2* within the cortex and cortical thickness and morphology obtained from 3 Tesla images were compared between CADASIL and control subjects using general linear models. MMSE, brain volume, cortical thickness and global sulcal morphology did not differ between groups. By contrast, T2* measured by 7 Tesla MRI was significantly increased in frontal, parietal, occipital and cingulate cortices in patients after correction for multiple testing. These changes were not related to white matter lesions, lacunes or microhemorrhages in patients having no brain atrophy compared to controls. Seven Tesla MRI, by contrast to state of the art post-processing of 3 Tesla acquisitions, shows diffuse T2* alterations within the cortical mantle in CADASIL whose origin remains to be determined.

  9. Adolescent Development of Cortical and White Matter Structure in the NCANDA Sample: Role of Sex, Ethnicity, Puberty, and Alcohol Drinking.

    Science.gov (United States)

    Pfefferbaum, Adolf; Rohlfing, Torsten; Pohl, Kilian M; Lane, Barton; Chu, Weiwei; Kwon, Dongjin; Nolan Nichols, B; Brown, Sandra A; Tapert, Susan F; Cummins, Kevin; Thompson, Wesley K; Brumback, Ty; Meloy, M J; Jernigan, Terry L; Dale, Anders; Colrain, Ian M; Baker, Fiona C; Prouty, Devin; De Bellis, Michael D; Voyvodic, James T; Clark, Duncan B; Luna, Beatriz; Chung, Tammy; Nagel, Bonnie J; Sullivan, Edith V

    2016-10-01

    Brain structural development continues throughout adolescence, when experimentation with alcohol is often initiated. To parse contributions from biological and environmental factors on neurodevelopment, this study used baseline National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA) magnetic resonance imaging (MRI) data, acquired in 674 adolescents meeting no/low alcohol or drug use criteria and 134 adolescents exceeding criteria. Spatial integrity of images across the 5 recruitment sites was assured by morphological scaling using Alzheimer's disease neuroimaging initiative phantom-derived volume scalar metrics. Clinical MRI readings identified structural anomalies in 11.4%. Cortical volume and thickness were smaller and white matter volumes were larger in older than in younger adolescents. Effects of sex (male > female) and ethnicity (majority > minority) were significant for volume and surface but minimal for cortical thickness. Adjusting volume and area for supratentorial volume attenuated or removed sex and ethnicity effects. That cortical thickness showed age-related decline and was unrelated to supratentorial volume is consistent with the radial unit hypothesis, suggesting a universal neural development characteristic robust to sex and ethnicity. Comparison of NCANDA with PING data revealed similar but flatter, age-related declines in cortical volumes and thickness. Smaller, thinner frontal, and temporal cortices in the exceeds-criteria than no/low-drinking group suggested untoward effects of excessive alcohol consumption on brain structural development. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. Proximity sensor technology for manipulator end effectors

    Science.gov (United States)

    Johnston, A. R.

    1975-01-01

    Optical proximity sensing techniques which could be used to help control the critical grasping phase of a remote manipulation are described. The proximity sensors described use a triangulation geometry to detect a surface located in a pre-determined region. The design of the proximity sensors themselves is discussed, as well as their application to manipulator control with a local control loop, and possibilities for future development are discussed.

  11. Genetic algorithms-based inversion of multimode guided waves for cortical bone characterization

    Science.gov (United States)

    Bochud, N.; Vallet, Q.; Bala, Y.; Follet, H.; Minonzio, J.-G.; Laugier, P.

    2016-10-01

    Recent progress in quantitative ultrasound has exploited the multimode waveguide response of long bones. Measurements of the guided modes, along with suitable waveguide modeling, have the potential to infer strength-related factors such as stiffness (mainly determined by cortical porosity) and cortical thickness. However, the development of such model-based approaches is challenging, in particular because of the multiparametric nature of the inverse problem. Current estimation methods in the bone field rely on a number of assumptions for pairing the incomplete experimental data with the theoretical guided modes (e.g. semi-automatic selection and classification of the data). The availability of an alternative inversion scheme that is user-independent is highly desirable. Thus, this paper introduces an efficient inversion method based on genetic algorithms using multimode guided waves, in which the mode-order is kept blind. Prior to its evaluation on bone, our proposal is validated using laboratory-controlled measurements on isotropic plates and bone-mimicking phantoms. The results show that the model parameters (i.e. cortical thickness and porosity) estimated from measurements on a few ex vivo human radii are in good agreement with the reference values derived from x-ray micro-computed tomography. Further, the cortical thickness estimated from in vivo measurements at the third from the distal end of the radius is in good agreement with the values delivered by site-matched high-resolution x-ray peripheral computed tomography.

  12. Inattention Predicts Increased Thickness of Left Occipital Cortex in Men with Attention-Deficit/Hyperactivity Disorder.

    Science.gov (United States)

    Sörös, Peter; Bachmann, Katharina; Lam, Alexandra P; Kanat, Manuela; Hoxhaj, Eliza; Matthies, Swantje; Feige, Bernd; Müller, Helge H O; Thiel, Christiane; Philipsen, Alexandra

    2017-01-01

    Attention-deficit/hyperactivity disorder (ADHD) in adulthood is a serious and frequent psychiatric disorder with the core symptoms inattention, impulsivity, and hyperactivity. The principal aim of this study was to investigate associations between brain morphology, i.e., cortical thickness and volumes of subcortical gray matter, and individual symptom severity in adult ADHD. Surface-based brain morphometry was performed in 35 women and 29 men with ADHD using FreeSurfer. Linear regressions were calculated between cortical thickness and the volumes of subcortical gray matter and the inattention, hyperactivity, and impulsivity subscales of the Conners Adult ADHD Rating Scales (CAARS). Two separate analyses were performed. For the first analysis, age was included as additional regressor. For the second analysis, both age and severity of depression were included as additional regressors. Study participants were recruited between June 2012 and January 2014. Linear regression identified an area in the left occipital cortex of men, covering parts of the middle occipital sulcus and gyrus, in which the score on the CAARS inattention subscale predicted increased mean cortical thickness [ F (1,27) = 26.27, p  gray matter and the scores on CAARS subscales, neither in men nor in women. These results remained stable when severity of depression was included as additional regressor, together with age. Increased cortical thickness in the left occipital cortex may represent a mechanism to compensate for dysfunctional attentional networks in male adult ADHD patients.

  13. Disentangling The Thick Concept Argument

    DEFF Research Database (Denmark)

    Blomberg, Olle

    2007-01-01

    Critics argue that non-cognitivism cannot adequately account for the existence and nature of some thick moral concepts. They use the existence of thick concepts as a lever in an argument against non-cognitivism, here called the Thick Concept Argument (TCA). While TCA is frequently invoked...

  14. Proximate composition and antinutrient content of pumpkin ...

    African Journals Online (AJOL)

    Proximate composition and antinutrient content of pumpkin ( Cucurbita pepo ) and sorghum ( Sorghum bicolor ) flour blends fermented with Lactobacillus plantarum , Aspergillus niger and Bacillus subtilis.

  15. Cortical consolidation of the radius and tibia in young men and women.

    Science.gov (United States)

    Walsh, Jennifer S; Paggiosi, Margaret A; Eastell, Richard

    2012-09-01

    Bone size, geometry, density, and microarchitecture are important determinants of bone strength. By understanding how these properties change during skeletal development, we can better understand bone fragility. The aim of the study was to compare the geometry, microarchitecture, and strength of the radius and tibia in men and women at the end of adolescence and in young adulthood and to relate these properties to biochemical bone turnover markers and bone regulatory hormones. We conducted a cross-sectional study of 116 healthy men and women ages 16-18 (n = 56) and 30-32 (n = 60) yr. We used high-resolution peripheral quantitative computed tomography to measure bone size, geometry, and microarchitecture at the distal radius and tibia and micro-finite element modeling to estimate bone strength. We measured bone turnover markers (β C-terminal telopeptide of type I collagen and amino-terminal propeptide of type I procollagen) and hormones known to affect bone metabolism (estradiol, testosterone, IGF-I, and PTH). Bone strength was greater in men than in women, and at the radius it was greater in men ages 30-32 yr than ages 16-18 yr. The gender difference was due to greater cortical perimeter, trabecular area, and trabecular density in men. The age difference was due to greater cortical thickness and cortical tissue mineral density and lower cortical porosity. IGF-I was related to two of these five key properties at the radius (cortical perimeter and cortical thickness). None of the hormones were predictors of density or structure at the tibia. Cortical modeling of long bones continues beyond the end of adolescence. IGF-I may be a determinant of this process at the radius.

  16. Primary visual cortical remapping in patients with inherited peripheral retinal degeneration.

    Science.gov (United States)

    Ferreira, Sónia; Pereira, Andreia Carvalho; Quendera, Bruno; Reis, Aldina; Silva, Eduardo Duarte; Castelo-Branco, Miguel

    2017-01-01

    Human studies addressing the long-term effects of peripheral retinal degeneration on visual cortical function and structure are scarce. Here we investigated this question in patients with Retinitis Pigmentosa (RP), a genetic condition leading to peripheral visual degeneration. We acquired functional and anatomical magnetic resonance data from thirteen patients with different levels of visual loss and twenty-two healthy participants to study primary (V1) visual cortical retinotopic remapping and cortical thickness. We identified systematic visual field remapping in the absence of structural changes in the primary visual cortex of RP patients. Remapping consisted in a retinotopic eccentricity shift of central retinal inputs to more peripheral locations in V1. Importantly, this was associated with changes in visual experience, as assessed by the extent of the visual loss, with more constricted visual fields resulting in larger remapping. This pattern of remapping is consistent with expansion or shifting of neuronal receptive fields into the cortical regions with reduced retinal input. These data provide evidence for functional changes in V1 that are dependent on the magnitude of peripheral visual loss in RP, which may be explained by rapid cortical adaptation mechanisms or long-term cortical reorganization. This study highlights the importance of analyzing the retinal determinants of brain functional and structural alterations for future visual restoration approaches.

  17. Improved explanation of human intelligence using cortical features with second order moments and regression.

    Science.gov (United States)

    Park, Hyunjin; Yang, Jin-ju; Seo, Jongbum; Choi, Yu-yong; Lee, Kun-ho; Lee, Jong-min

    2014-04-01

    Cortical features derived from magnetic resonance imaging (MRI) provide important information to account for human intelligence. Cortical thickness, surface area, sulcal depth, and mean curvature were considered to explain human intelligence. One region of interest (ROI) of a cortical structure consisting of thousands of vertices contained thousands of measurements, and typically, one mean value (first order moment), was used to represent a chosen ROI, which led to a potentially significant loss of information. We proposed a technological improvement to account for human intelligence in which a second moment (variance) in addition to the mean value was adopted to represent a chosen ROI, so that the loss of information would be less severe. Two computed moments for the chosen ROIs were analyzed with partial least squares regression (PLSR). Cortical features for 78 adults were measured and analyzed in conjunction with the full-scale intelligence quotient (FSIQ). Our results showed that 45% of the variance of the FSIQ could be explained using the combination of four cortical features using two moments per chosen ROI. Our results showed improvement over using a mean value for each ROI, which explained 37% of the variance of FSIQ using the same set of cortical measurements. Our results suggest that using additional second order moments is potentially better than using mean values of chosen ROIs for regression analysis to account for human intelligence. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Thick Disks of Lenticular Galaxies

    OpenAIRE

    Pohlen, M.; Balcells, M.; Luetticke, R.; Dettmar, R. -J.

    2004-01-01

    Thick disks are faint and extended stellar components found around several disk galaxies including our Milky Way. The Milky Way thick disk, the only one studied in detail, contains mostly old disk stars (~10 Gyr), so that thick disks are likely to trace the early stages of disk evolution. Previous detections of thick disk stellar light in external galaxies have been originally made for early-type, edge-on galaxies but detailed 2D thick/thin disk decompositions have been reported for only a sc...

  19. Trabecular and cortical bone separately assessed at radius with a new ultrasound device, in a young adult population with various physical activities.

    Science.gov (United States)

    Bréban, S; Padilla, F; Fujisawa, Y; Mano, I; Matsukawa, M; Benhamou, C L; Otani, T; Laugier, P; Chappard, C

    2010-06-01

    The aim was to evaluate a new ultrasound device in a young adult population and to assess its reproducibility via comparison to DXA measurements and geometrical measurements from high-resolution radiographs. Ninety-three subjects aged between 20 and 51 years were recruited and divided into four groups according to their gender and physical activity status: 22 male athletes, 19 male controls, 21 female athletes, and 31 female controls. Ultrasonic measurements were assessed by the prototype LD-100 (Oyo Electric Co., Kyoto, Japan) on the dominant distal radius. Attenuation in the radius (dB), cortical bone thickness (mm), radius thickness (mm), mass density of cancellous bone (mg/cm(3)), and elasticity (GPa) of cancellous bone were obtained. BMD was measured by DXA at the dominant distal radius. Radius images were obtained with a direct high-resolution digital X-ray device (BMA, D(3)A Medical Systems), and radius and cortical thicknesses were estimated using a specific software (ImageJ, Bethesda, USA), in an area site-matched with LD-100. There was a significant positive correlation between site-matched BMD measurement and LD-100 parameters (pX-ray radius thickness, and LD-100 parameters except elasticity (p0.32), X-ray cortical thickness and LD-100 attenuation and cortical thickness (pradius thicknesses were found in athletes compared to controls (pradius thickness measured on radiographs was significantly higher in athletes versus controls in both sexes, and cortical thickness was significantly higher in male athletes versus controls. These data suggest a positive influence of physical activity on bone cortical measurements. This study also confirmed the particular interest of bone assessment by ultrasound. Copyright 2010 Elsevier Inc. All rights reserved.

  20. Rapid cortical bone loss in patients with chronic kidney disease.

    Science.gov (United States)

    Nickolas, Thomas L; Stein, Emily M; Dworakowski, Elzbieta; Nishiyama, Kyle K; Komandah-Kosseh, Mafo; Zhang, Chiyuan A; McMahon, Donald J; Liu, Xiaowei S; Boutroy, Stephanie; Cremers, Serge; Shane, Elizabeth

    2013-08-01

    Chronic kidney disease (CKD) patients may have high rates of bone loss and fractures, but microarchitectural and biochemical mechanisms of bone loss in CKD patients have not been fully described. In this longitudinal study of 53 patients with CKD Stages 2 to 5D, we used dual-energy X-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HRpQCT), and biochemical markers of bone metabolism to elucidate effects of CKD on the skeleton. Median follow-up was 1.5 years (range 0.9 to 4.3 years); bone changes were annualized and compared with baseline. By DXA, there were significant declines in areal bone mineral density (BMD) of the total hip and ultradistal radius: -1.3% (95% confidence interval [CI] -2.1 to -0.6) and -2.4% (95% CI -4.0 to -0.9), respectively. By HRpQCT at the distal radius, there were significant declines in cortical area, density, and thickness and increases in porosity: -2.9% (95% CI -3.7 to -2.2), -1.3% (95% CI -1.6 to -0.6), -2.8% (95% CI -3.6 to -1.9), and +4.2% (95% CI 2.0 to 6.4), respectively. Radius trabecular area increased significantly: +0.4% (95% CI 0.2 to 0.6), without significant changes in trabecular density or microarchitecture. Elevated time-averaged levels of parathyroid hormone (PTH) and bone turnover markers predicted cortical deterioration. Higher levels of serum 25-hydroxyvitamin D predicted decreases in trabecular network heterogeneity. These data suggest that significant cortical loss occurs with CKD, which is mediated by hyperparathyroidism and elevated turnover. Future investigations are required to determine whether these cortical losses can be attenuated by treatments that reduce PTH levels and remodeling rates. Copyright © 2013 American Society for Bone and Mineral Research.

  1. Spreading depression and focal venous cerebral ischemia enhance cortical neurogenesis

    Directory of Open Access Journals (Sweden)

    Ryo Tamaki

    2017-01-01

    Full Text Available Endogenous neurogenesis can arise from a variety of physiological stimuli including exercise, learning, or “enriched environment” as well as pathological conditions such as ischemia, epilepsy or cortical spreading depression. Whether all these conditions use a common trigger to set off endogenous neurogenesis is yet unclear. We hypothesized that cortical spreading depression (CSD induces neurogenesis in the cerebral cortex and dentate gyrus after cerebral venous ischemia. Forty-two Wistar rats alternatively underwent sham operation (Sham, induction of ten CSDs or venous ischemia provoked via occlusion of two adjacent superficial cortical vein followed by ten induced CSDs (CSD + 2-VO. As an additional control, 15 naïve rats received no intervention except 5-bromo-2′-deoxyuridine (BrdU treatment for 7 days. Sagittal brain slices (40 μm thick were co-stained for BrdU and doublecortin (DCX; new immature neuronal cells on day 9 or NeuN (new mature neuronal cells on day 28. On day 9 after sham operation, cell proliferation and neurogenesis occurred in the cortex in rats. The sole induction of CSD had no effect. But on days 9 and 28, more proliferating cells and newly formed neurons in the ipsilateral cortex were observed in rats subjected to CSD + 2VO than in rats subjected to sham operation. On days 9 and 28, cell proliferation and neurogenesis in the ipsilateral dentate gyrus was increased in sham-operated rats than in naïve rats. Our data supports the hypothesis that induced cortical neurogenesis after CSD + 2-VO is a direct effect of ischemia, rather than of CSD alone.

  2. Better Axial Stiffness of a Bicortical Screw Construct Compared to a Cable Construct for Comminuted Vancouver B1 Proximal Femoral Fractures.

    Science.gov (United States)

    Griffiths, Jamie T; Taheri, Arash; Day, Robert E; Yates, Piers J

    2015-12-01

    The aim of this study was to biomechanically evaluate the Locking attachment plate (LAP) construct in comparison to a Cable plate construct, for the fixation of periprosthetic femoral fractures after cemented total hip arthroplasty. Each construct incorporated a locking compression plate with bi-cortical locking screws for distal fixation. In the Cable construct, 2 cables and 2 uni-cortical locking screws were used for proximal fixation. In the LAP construct, the cables were replaced by a LAP with 4 bi-cortical locking screws. The LAP construct was significantly stiffer than the cable construct under axial load with a bone gap (P=0.01). The LAP construct offers better axial stiffness compared to the cable construct in the fixation of comminuted Vancouver B1 proximal femoral fractures. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  3. Use of B-mode ultrasonography for measuring femoral muscle thickness in dogs.

    Science.gov (United States)

    Sakaeda, Kanako; Shimizu, Miki

    2016-06-01

    Assessment of muscle mass is important for evaluating muscle function and rehabilitation outcomes. Ultrasound has recently been successfully used to estimate muscle mass in humans by measuring muscle thickness. This study attempted to standardize procedures for measuring femoral muscle thickness ultrasonographically, as well as quantify the reliability and validity of ultrasound evaluations of muscle thickness compared to measurements made by magnetic resonance imaging (MRI) in dogs. We evaluated the quadriceps femoris (QF), biceps femoris (BF), semitendinosus (ST) and semimembranosus (SM) muscles of 10 clinically healthy Beagle dogs. Scans were taken in 5 different sections divided equally between the greater trochanter and proximal patella. MRI was performed, followed by T1-weighted and contrast-enhanced T1-weighted imaging. Muscle cross-sectional area (CSA) was measured with MRI, and muscle thickness was measured with MRI and ultrasonography. The thickness of the QF, BF and ST muscles as measured by ultrasound at slices 1-3 (from the proximal end to the middle of the femur), 2-4 (middle of the femur) and 2 (more proximal than the middle of the femur), respectively, was correlated with muscle thickness and CSA as measured by MRI. These sites showed a flat interface between muscle and transducer and were situated over belly muscle. No correlation between measurement types was seen in SM muscle. We must confirm this assessment method for various breeds, sizes, ages and muscle pathologies in dogs, thereby confirming that muscle thickness as measured ultrasonographically can reflect muscle function.

  4. Functional outcome following proximal humeral interlocking system plating for displaced proximal humeral fractures

    OpenAIRE

    Thyagarajan David; Haridas Samarth; Jones Denise; Dent Colin; Evans Richard; Williams Rhys

    2009-01-01

    Aim: To assess the functional outcome following internal fixation with the PHILOS (proximal humeral interlocking system) for displaced proximal humeral fractures. Patients and Methods: We reviewed 30 consecutive patients treated surgically with the proximal humeral locking plate for a displaced proximal humeral fracture. Functional outcome was determined using the American Shoulder and Elbow Society (ASES) score and Constant Murley score. Results: Average age of the patients was 58 years...

  5. Best Proximity Points for a New Class of Generalized Proximal Mappings

    Directory of Open Access Journals (Sweden)

    Tayyab Kamran

    2017-03-01

    Full Text Available The best proximity points are usually used to find the optimal approximate solution of the operator equation Tx = x, when T has no fixed point. In this paper, we prove some best proximity point theorems for nonself multivalued operators, following the foot steps of Basha and Shahzad [Best proximity point theorems for generalized proximal contractions, Fixed Point Theory Appl., 2012, 2012:42].

  6. Improve Static Performance Identification Of Inductive Proximity Sensor For a Mobile Robot

    Directory of Open Access Journals (Sweden)

    Hoai Nguyen

    2016-01-01

    Full Text Available Nowadays, inductive proximity sensor and mobile robot are one of the most interesting topics attracting scientists. With enhancement techniques from using sensor for controlling mobile robots which can be developed more in the future. Additionally, measuring of static performance of inductive proximity sensor is also essential because the testing and navigation systems perform more exactly by result information from the experiment by assaying the output signal. In this paper, the hand-made measurement system is used to verify again the static performance of proximity sensor with ferrous, non-ferrous and alloy metal tape. Simultaneously, improve static properties of typical tape metal through the relationship between the output signal and the sensing distance of sensor. According to theoretical basis, the relationship of the static parameters can be determined such as: thickness of metal, sensing distance, dimension of metal, and so on. The testing results have shown the output signal of proximity sensor in the model and theory is not similar. The final data will accommodate some information about the relationship of the thickness of metal tape and the sensing distance of proximity sensor, the different affects of position sensor and optimum operation range of mobile robot.

  7. Proximity effect in Nb/Al, AlOxide, Al/Nb Josephson tunnel junctions

    Science.gov (United States)

    Houwman, E. P.; Gijsbertsen, J. G.; Flokstra, J.; Rogalla, H.; Le Grand, J. B.; de Korte, P. A. J.; Golubov, A. A.

    1993-03-01

    Regions with reduced energy gap induced by the proximity effect give rise to quasi-particle loss in Josephson-junction X-ray detectors, but may also be used advantageously for quasi-particle collection. The influence of the thickness of the Al proximity layers in Nb/Al1,AlO(x),Al2/Nb Josephson tunnel junctions on the electrical characteristics has been investigated theoretically and experimentally. Theoretically it is found that the strength of the proximity effect is mainly determined by the proximity parameters gammaM1 (gammaM2) of the electrodes. Good fits of the measured I-V curves with theory were obtained for junctions with thicknesses dA11 ranging from 4 to 25 nm and dA12 = 3 nm, with gammaM2 about 0.12 and gammaM1/gammaM2 = dA11/dA12. For all junctions the proximity knee remains more pronounced than predicted.

  8. Inattention Predicts Increased Thickness of Left Occipital Cortex in Men with Attention-Deficit/Hyperactivity Disorder

    Directory of Open Access Journals (Sweden)

    Peter Sörös

    2017-09-01

    Full Text Available BackgroundAttention-deficit/hyperactivity disorder (ADHD in adulthood is a serious and frequent psychiatric disorder with the core symptoms inattention, impulsivity, and hyperactivity. The principal aim of this study was to investigate associations between brain morphology, i.e., cortical thickness and volumes of subcortical gray matter, and individual symptom severity in adult ADHD.MethodsSurface-based brain morphometry was performed in 35 women and 29 men with ADHD using FreeSurfer. Linear regressions were calculated between cortical thickness and the volumes of subcortical gray matter and the inattention, hyperactivity, and impulsivity subscales of the Conners Adult ADHD Rating Scales (CAARS. Two separate analyses were performed. For the first analysis, age was included as additional regressor. For the second analysis, both age and severity of depression were included as additional regressors. Study participants were recruited between June 2012 and January 2014.ResultsLinear regression identified an area in the left occipital cortex of men, covering parts of the middle occipital sulcus and gyrus, in which the score on the CAARS inattention subscale predicted increased mean cortical thickness [F(1,27 = 26.27, p < 0.001, adjusted R2 = 0.4744]. No significant associations were found between cortical thickness and the scores on CAARS subscales in women. No significant associations were found between the volumes of subcortical gray matter and the scores on CAARS subscales, neither in men nor in women. These results remained stable when severity of depression was included as additional regressor, together with age.ConclusionIncreased cortical thickness in the left occipital cortex may represent a mechanism to compensate for dysfunctional attentional networks in male adult ADHD patients.

  9. Communication and wiring in the cortical connectome

    Science.gov (United States)

    Budd, Julian M. L.; Kisvárday, Zoltán F.

    2012-01-01

    In cerebral cortex, the huge mass of axonal wiring that carries information between near and distant neurons is thought to provide the neural substrate for cognitive and perceptual function. The goal of mapping the connectivity of cortical axons at different spatial scales, the cortical connectome, is to trace the paths of information flow in cerebral cortex. To appreciate the relationship between the connectome and cortical function, we need to discover the nature and purpose of the wiring principles underlying cortical connectivity. A popular explanation has been that axonal length is strictly minimized both within and between cortical regions. In contrast, we have hypothesized the existence of a multi-scale principle of cortical wiring where to optimize communication there is a trade-off between spatial (construction) and temporal (routing) costs. Here, using recent evidence concerning cortical spatial networks we critically evaluate this hypothesis at neuron, local circuit, and pathway scales. We report three main conclusions. First, the axonal and dendritic arbor morphology of single neocortical neurons may be governed by a similar wiring principle, one that balances the conservation of cellular material and conduction delay. Second, the same principle may be observed for fiber tracts connecting cortical regions. Third, the absence of sufficient local circuit data currently prohibits any meaningful assessment of the hypothesis at this scale of cortical organization. To avoid neglecting neuron and microcircuit levels of cortical organization, the connectome framework should incorporate more morphological description. In addition, structural analyses of temporal cost for cortical circuits should take account of both axonal conduction and neuronal integration delays, which appear mostly of the same order of magnitude. We conclude the hypothesized trade-off between spatial and temporal costs may potentially offer a powerful explanation for cortical wiring patterns

  10. Acute hepatic encephalopathy with diffuse cortical lesions

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, S.M.; Spreer, J.; Schumacher, M. [Section of Neuroradiology, Univ. of Freiburg (Germany); Els, T. [Dept. of Neurology, University of Freiburg (Germany)

    2001-07-01

    Acute hepatic encephalopathy is a poorly defined syndrome of heterogeneous aetiology. We report a 49-year-old woman with alcoholic cirrhosis and hereditary haemorrhagic telangiectasia who developed acute hepatic coma induced by severe gastrointestinal bleeding. Laboratory analysis revealed excessively elevated blood ammonia. MRI showed lesions compatible with chronic hepatic encephalopathy and widespread cortical signal change sparing the perirolandic and occipital cortex. The cortical lesions resembled those of hypoxic brain damage and were interpreted as acute toxic cortical laminar necrosis. (orig.)

  11. Preliminary phytochemical screening, proximate and elemental ...

    African Journals Online (AJOL)

    The seed powder of Moringa oleifera was analysed for its phytochemical, proximate and elemental composition using Folin-Denis spectrophotometric method, gravimetric method and energy dispersing X-ray fluorescence (EDXRF) transmission emission technique respectively. The seed powder had the following proximate ...

  12. Bimalleolar ankle fracture with proximal fibular fracture

    NARCIS (Netherlands)

    Colenbrander, R. J.; Struijs, P. A. A.; Ultee, J. M.

    2005-01-01

    A 56-year-old female patient suffered a bimalleolar ankle fracture with an additional proximal fibular fracture. This is an unusual fracture type, seldom reported in literature. It was operatively treated by open reduction and internal fixation of the lateral malleolar fracture. The proximal fibular

  13. Grouping by Proximity in Haptic Contour Detection

    Science.gov (United States)

    Overvliet, Krista E.; Krampe, Ralf Th.; Wagemans, Johan

    2013-01-01

    We investigated the applicability of the Gestalt principle of perceptual grouping by proximity in the haptic modality. To do so, we investigated the influence of element proximity on haptic contour detection. In the course of four sessions ten participants performed a haptic contour detection task in which they freely explored a haptic random dot display that contained a contour in 50% of the trials. A contour was defined by a higher density of elements (raised dots), relative to the background surface. Proximity of the contour elements as well as the average proximity of background elements was systematically varied. We hypothesized that if proximity of contour elements influences haptic contour detection, detection will be more likely when contour elements are in closer proximity. This should be irrespective of the ratio with the proximity of the background elements. Results showed indeed that the closer the contour elements were, the higher the detection rates. Moreover, this was the case independent of the contour/background ratio. We conclude that the Gestalt law of proximity applies to haptic contour detection. PMID:23762364

  14. Proximate analysis on four edible mushrooms ADEDAYO ...

    African Journals Online (AJOL)

    Michael Horsfall

    Vol. 15 (1) 9 - 11. Full-text Available Online at www.bioline.org.br/ja. Proximate analysis on four edible mushrooms. ADEDAYO, MAJEKODUNMI RACHEL. Nigerian Stored Product Research Institute, P.M.B.3032, Kano. ABSTRACT: Proximate study was conducted on four edible mushrooms commonly found in farmlands in.

  15. Proximate Sources of Collective Teacher Efficacy

    Science.gov (United States)

    Adams, Curt M.; Forsyth, Patrick B.

    2006-01-01

    Purpose: Recent scholarship has augmented Bandura's theory underlying efficacy formation by pointing to more proximate sources of efficacy information involved in forming collective teacher efficacy. These proximate sources of efficacy information theoretically shape a teacher's perception of the teaching context, operationalizing the difficulty…

  16. Phytochemical screening, proximate analysis and anticonvulsant ...

    African Journals Online (AJOL)

    Spigelia anthelmia is used traditionally in Southern Nigeria for the treatment of infant convulsion and epilepsy. This study investigated the phytochemical constituents, proximate analysis and anticonvulsant effect of the methanolic extract of Spigelia anthelmia. Phytochemical evaluation and proximate analysis was carried ...

  17. Effect of gender, age and anthropometric variables on plantar fascia thickness at different locations in asymptomatic subjects

    Energy Technology Data Exchange (ETDEWEB)

    Pascual Huerta, Javier [Department of Podiatry, Universidad Europea de Madrid (Spain)]. E-mail: javier.pascual@uem.es; Alarcon Garcia, Juan Maria [Ultrasound Unit, Hospital Nuestra Senora de America, Madrid (Spain)

    2007-06-15

    Purpose: The study was aimed to investigate plantar fascia thickness at different locations in healthy asymptomatic subjects and its relationship to the following variables: weight, height, sex and age. Material and methods: The study evaluates 96 feet of healthy asymptomatic volunteers. The plantar fascia thickness was measured at four different locations: 1 cm proximal to the insertion of the plantar fascia, at the insertion of the plantar fascia on the calcaneus and separate out 1 cm + 2 cm distal to the insertion. A 10 MHz linear-array transducer was used. Results: There were statistically significant differences in plantar fascia thickness at the four different locations (p < 0.001) although no differences in PF thickness were found between the two distal from insertion locations (1 and 2 cm). Multiple regression analysis showed sex as independent predictor of plantar fascia thickness at 1 cm proximal to the insertion. At origin and 1 cm distal to insertion weight was an independent predictor of plantar fascia thickness. Conclusions: There are differences of thickness at different locations of plantar fascia measured by ultrasonography. Thickness at 1 cm proximal to the insertion is influenced by sex and thickness at origin and at 1 cm distal to the insertion has a direct relationship with body weight. This could be attributed to the overloading effect that weight has on plantar fascia in healthy symptomatic subjects at these two locations. Height and age did not seem to influence as independent variables in plantar fascia thickness among non-painful subjects.

  18. Decreased cortical inhibition and yet cerebellar pathology in 'familial cortical myoclonic tremor with epilepsy'

    NARCIS (Netherlands)

    van Rootselaar, Anne-Fleur; van der Salm, Sandra M. A.; Bour, Lo J.; Edwards, Mark J.; Brown, Peter; Aronica, Eleonora; Rozemuller-Kwakkel, Johanna M.; Koehler, Peter J.; Koelman, Johannes H. T. M.; Rothwell, John C.; Tijssen, Marina A. J.

    2007-01-01

    Cortical hyperexcitability is a feature of "familial cortical myoclonic tremor with epilepsy" (FCMTE). However, neuropathological investigations in a single FCMTE patient showed isolated cerebellar pathology. Pathological investigations in a second FCMTE patient, reported here, confirmed cerebellar

  19. Mild exercise early in life produces changes in bone size and strength but not density in proximal phalangeal, third metacarpal and third carpal bones of foals.

    Science.gov (United States)

    Firth, Elwyn C; Rogers, Christopher W; van Weeren, P Rene; Barneveld, Albert; McIlwraith, C Wayne; Kawcak, Christopher E; Goodship, Allen E; Smith, Roger K W

    2011-12-01

    Exercise or lack of it in early life affects chondro-osseous development. Two groups of horses were used to investigate the effects of age and exercise regimen on bone parameters of diaphyseal, metaphyseal, epiphyseal and cuboidal bones of the distal limb of Thoroughbreds. One group had exercised only spontaneously from an early age at pasture (PASTEX group), while the other group of horses were exposed to a 30% greater workload through additional defined exercise (CONDEX). Longitudinal data from peripheral quantitative computed tomography (pQCT) were obtained from eight scan sites of the left forelimb (proximal phalangeal (P(p); 1 site), third metacarpal (Mc3; six sites) and third carpal (C(3); one site) bones) of 32 Thoroughbred foals scanned five times from ∼3 weeks to 17 months of age. The primary outcome measures were bone mineral content (BMC), bone area (BA), and periosteal circumference (Peri C) in diaphyseal bone, with cortical thickness (CortTh), volumetric bone mineral density (BMD(v)) and a bone strength index (SSI) also being analysed. At the P(p) site within the model there was a significant effect (P=0.00-0.025) of conditioning exercise increasing bone parameters, except endosteal circumference (Endo C) and BMD(v). The BMC, BA, and SSI of P(p) were significantly greater in the CONDEX than PASTEX groups at 12 and 17 months (P=0.015-0.042) and CortTh at 17 months (P=0.033). At the M55 site of Mc3 BMC, BA and SSI (P=0.02-0.04), and at the M33 site, SSI (P=0.05) were higher in the CONDEX than PASTEX group. The adaptive responses, consistent with diaphyseal strengthening, were more marked in the diaphysis of P(p) than Mc3. In the Mc3, metaphysis, trabecular BMD(v) was less in the CONDEX than PASTEX group, associated with greater bone mineral accretion in the outer cortical-sub-cortical bone in the CONDEX group. There were no significant between-group differences in any epiphyseal or cuboidal bone parameter. Although the early imposed exercise regimen

  20. Cortical Strut Allograft Support of Modular Femoral Junctions During Revision Total Hip Arthroplasty.

    Science.gov (United States)

    Lim, Chin Tat; Amanatullah, Derek F; Huddleston, James I; Hwang, Katherine L; Maloney, William J; Goodman, Stuart B

    2017-05-01

    There is risk of junction failure when using modular femoral stems for revision total hip arthroplasty (THA), especially with loss of bone stock in the proximal femur. Using a cortical strut allograft may provide additional support of a modular femoral construct in revision THA. We reviewed prospectively gathered clinical and radiographic data for 28 revision THAs performed from 2004 to 2014 using cementless modular femoral components with cortical strut allograft applied to supplement proximal femoral bone loss: 5 (18%) were fluted taper designs and 23 (82%) were porous cylindrical designs All the patients had a Paprosky grade IIIA or greater femoral defect. The mean follow-up was 5.4 ± 3.9 years. The Harris Hip Scores improved from 26 ± 10 points preoperatively to 71 ± 10 points at final follow-up (P < .001). The Western Ontario McMaster Universities Osteoarthritis Index scores improved from 45 ± 12 points preoperatively to 76 ± 12 points at final follow-up (P < .001). Eighty-nine percent (25 hips) of all revision or conversion THAs were in place at final follow-up. Three (11%) patients underwent reoperations, 2 for infection and 1 for periprosthetic fracture. There was no statistical significant change in femoral component alignment (P = .161) at final follow-up. Mean subsidence was 1.8 ± 1.3 mm at final follow-up. Femoral diameter increased from initial postoperative imaging to final follow-up imaging by a mean of 9.1 ± 5.1 mm (P < .001) and cortical width increased by a mean of 4.5 ± 2.2 mm (P < .001). Twenty-seven hips (96%) achieved union between the cortical strut allograft and the host femur. The use of a modular femoral stem in a compromised femur with a supplementary cortical strut allgraft is safe and provides satisfactory clinical and radiological outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Intramedullary compression device for proximal ulna fracture.

    Science.gov (United States)

    Hong, Choon Chiet; Han, Fucai; Decruz, Joshua; Pannirselvam, Vinodhkumar; Murphy, Diarmuid

    2015-02-01

    Proximal ulna fractures account for 20% of all proximal forearm fractures. Many treatment options are available for such fractures, such as cast immobilisation, plate and screw fixation, tension band wiring and intramedullary screw fixation, depending on the fracture pattern. Due to the subcutaneous nature of the proximal forearm, it is vulnerable to open injuries over the dorsal aspect of the proximal ulna. This may in turn prove challenging, as it is critical to obtain adequate soft tissue coverage to reduce the risk of implant exposure and bony infections. We herein describe a patient with a Gustillo III-B open fracture of the proximal ulna, treated with minimally invasive intramedullary screw fixation using a 6.0-mm cannulated headless titanium compression screw (FusiFIX, Péronnas, France).

  2. Tibial Plateau Leveling Osteotomy Plate Contouring and Proximal Load Screw Angulation Affect Osteotomy Compression.

    Science.gov (United States)

    Mathis, Karl R; Roe, Simon C; Johnson, Kenneth A

    2015-11-01

    To evaluate the effect of contouring a tibial plateau leveling osteotomy (TPLO) plate, the associated angulation of the dynamic compression plate (DCP) hole relative to the long axis of the tibia, and angulation of the screw relative to the DCP hole on the osteotomy compression generated by load screws in a TPLO model. In vitro biomechanical study. Polyoxymethylene (POM) rod and synthetic cortical bone substitute model (n = 9). The distal portion of a Slocum TPLO plate was attached to a horizontally positioned POM rod that was connected to a load cell. A segment of synthetic cortical bone substitute was attached to the end mount of the testing frame and adjusted to conform to the angle of the proximal portion of the TPLO plate. A 3.5 mm cortical bone screw was inserted in the proximal DCP hole and tightened to 1.5 Nm. The peak longitudinal load (N) was recorded. Screw insertion and data collection were repeated for proximal plate angles of 0-40° at 5° increments. A significant increase in the compression generated was observed as the plate angle was increased from 0° to 10°. The compression ceased to significantly increase until the plate was bent more than 20°, after which a significant decrease in compression was noted. A marked reduction in the compression generated occurred at plate angles greater than 30°. Angulation of the DCP hole and screw insertion angle can have deleterious effects on the magnitude of osteotomy compression. © Copyright 2015 by The American College of Veterinary Surgeons.

  3. Cushing, Penfield, and cortical stimulation.

    Science.gov (United States)

    Leblanc, Richard

    2018-01-26

    Harvey Cushing and Wilder Penfield enjoyed a unique professional and personal relationship. Shortly before his retirement from Harvard University in 1933, Cushing sent Penfield 8 sketches that he drew in 1902 and 1903 while he was at Johns Hopkins Hospital. The first series of 3 sketches illustrate the relationship between a cortical hemorrhagic lesion and the motor strip in a patient with focal motor seizures. The second series also comprises 3 sketches. These depict the operative findings in a patient in whom Cushing had electrically stimulated the precentral gyrus, before resecting the cortex subserving motility of the upper extremity to control painful dyskinetic movements. The third series consists of 2 sketches that illustrate the results of stimulation of the motor strip as an aid in the safe resection of an epileptogenic focus in a patient with Jacksonian seizures. These sketches are the subjects of this paper. They add to the relatively sparse record of Cushing's activities in cortical stimulation and in the treatment of functional disorders.

  4. SLEEP AND OLFACTORY CORTICAL PLASTICITY

    Directory of Open Access Journals (Sweden)

    Dylan eBarnes

    2014-04-01

    Full Text Available In many systems, sleep plays a vital role in memory consolidation and synaptic homeostasis. These processes together help store information of biological significance and reset synaptic circuits to facilitate acquisition of information in the future. In this review, we describe recent evidence of sleep-dependent changes in olfactory system structure and function which contribute to odor memory and perception. During slow-wave sleep, the piriform cortex becomes hypo-responsive to odor stimulation and instead displays sharp-wave activity similar to that observed within the hippocampal formation. Furthermore, the functional connectivity between the piriform cortex and other cortical and limbic regions is enhanced during slow-wave sleep compared to waking. This combination of conditions may allow odor memory consolidation to occur during a state of reduced external interference and facilitate association of odor memories with stored hedonic and contextual cues. Evidence consistent with sleep-dependent odor replay within olfactory cortical circuits is presented. These data suggest that both the strength and precision of odor memories is sleep-dependent. The work further emphasizes the critical role of synaptic plasticity and memory in not only odor memory but also basic odor perception. The work also suggests a possible link between sleep disturbances that are frequently co-morbid with a wide range of pathologies including Alzheimer’s disease, schizophrenia and depression and the known olfactory impairments associated with those disorders.

  5. Cortical control of facial expression.

    Science.gov (United States)

    Müri, René M

    2016-06-01

    The present Review deals with the motor control of facial expressions in humans. Facial expressions are a central part of human communication. Emotional face expressions have a crucial role in human nonverbal behavior, allowing a rapid transfer of information between individuals. Facial expressions can be either voluntarily or emotionally controlled. Recent studies in nonhuman primates and humans have revealed that the motor control of facial expressions has a distributed neural representation. At least five cortical regions on the medial and lateral aspects of each hemisphere are involved: the primary motor cortex, the ventral lateral premotor cortex, the supplementary motor area on the medial wall, and the rostral and caudal cingulate cortex. The results of studies in humans and nonhuman primates suggest that the innervation of the face is bilaterally controlled for the upper part and mainly contralaterally controlled for the lower part. Furthermore, the primary motor cortex, the ventral lateral premotor cortex, and the supplementary motor area are essential for the voluntary control of facial expressions. In contrast, the cingulate cortical areas are important for emotional expression, because they receive input from different structures of the limbic system. © 2015 Wiley Periodicals, Inc.

  6. Automated cortical bone segmentation for multirow-detector CT imaging with validation and application to human studies.

    Science.gov (United States)

    Li, Cheng; Jin, Dakai; Chen, Cheng; Letuchy, Elena M; Janz, Kathleen F; Burns, Trudy L; Torner, James C; Levy, Steven M; Saha, Punam K

    2015-08-01

    Cortical bone supports and protects human skeletal functions and plays an important role in determining bone strength and fracture risk. Cortical bone segmentation at a peripheral site using multirow-detector CT (MD-CT) imaging is useful for in vivo assessment of bone strength and fracture risk. Major challenges for the task emerge from limited spatial resolution, low signal-to-noise ratio, presence of cortical pores, and structural complexity over the transition between trabecular and cortical bones. An automated algorithm for cortical bone segmentation at the distal tibia from in vivo MD-CT imaging is presented and its performance and application are examined. The algorithm is completed in two major steps-(1) bone filling, alignment, and region-of-interest computation and (2) segmentation of cortical bone. After the first step, the following sequence of tasks is performed to accomplish cortical bone segmentation-(1) detection of marrow space and possible pores, (2) computation of cortical bone thickness, detection of recession points, and confirmation and filling of true pores, and (3) detection of endosteal boundary and delineation of cortical bone. Effective generalizations of several digital topologic and geometric techniques are introduced and a fully automated algorithm is presented for cortical bone segmentation. An accuracy of 95.1% in terms of volume of agreement with manual outlining of cortical bone was observed in human MD-CT scans, while an accuracy of 88.5% was achieved when compared with manual outlining on postregistered high resolution micro-CT imaging. An intraclass correlation coefficient of 0.98 was obtained in cadaveric repeat scans. A pilot study was conducted to describe gender differences in cortical bone properties. This study involved 51 female and 46 male participants (age: 19-20 yr) from the Iowa Bone Development Study. Results from this pilot study suggest that, on average after adjustment for height and weight differences, males have

  7. Cortical structure of hallucal metatarsals and locomotor adaptations in hominoids.

    Directory of Open Access Journals (Sweden)

    Tea Jashashvili

    Full Text Available Diaphyseal morphology of long bones, in part, reflects in vivo loads experienced during the lifetime of an individual. The first metatarsal, as a cornerstone structure of the foot, presumably expresses diaphyseal morphology that reflects loading history of the foot during stance phase of gait. Human feet differ substantially from those of other apes in terms of loading histories when comparing the path of the center of pressure during stance phase, which reflects different weight transfer mechanisms. Here we use a novel approach for quantifying continuous thickness and cross-sectional geometric properties of long bones in order to test explicit hypotheses about loading histories and diaphyseal structure of adult chimpanzee, gorilla, and human first metatarsals. For each hallucal metatarsal, 17 cross sections were extracted at regularly-spaced intervals (2.5% length between 25% and 65% length. Cortical thickness in cross sections was measured in one degree radially-arranged increments, while second moments of area were measured about neutral axes also in one degree radially-arranged increments. Standardized thicknesses and second moments of area were visualized using false color maps, while penalized discriminant analyses were used to evaluate quantitative species differences. Humans systematically exhibit the thinnest diaphyseal cortices, yet the greatest diaphyseal rigidities, particularly in dorsoplantar regions. Shifts in orientation of maximum second moments of area along the diaphysis also distinguish human hallucal metatarsals from those of chimpanzees and gorillas. Diaphyseal structure reflects different loading regimes, often in predictable ways, with human versus non-human differences probably resulting both from the use of arboreal substrates by non-human apes and by differing spatial relationships between hallux position and orientation of the substrate reaction resultant during stance. The novel morphological approach employed in

  8. Bone mineral loss at the proximal femur in acute spinal cord injury.

    Science.gov (United States)

    Edwards, W B; Schnitzer, T J; Troy, K L

    2013-09-01

    This study used quantitative computed tomography to assess changes in bone mineral at the proximal femur after acute spinal cord injury (SCI). Individuals with acute SCI experienced a marked loss of bone mineral from a combination of trabecular and endocortical resorption. Targeted therapeutic interventions are thus warranted in this population. SCI is associated with a rapid loss of bone mineral and an increased rate of fragility fracture. Some 10 to 20% of these fractures occur at the proximal femur. The purpose of this study was to quantify changes to bone mineral, geometry, and measures of strength at the proximal femur in acute SCI. Quantitative computed tomography analysis was performed on 13 subjects with acute SCI at serial time points separated by a mean of 3.5 months (range, 2.6-4.8 months). Changes in bone mineral content (BMC) and volumetric bone mineral density (vBMD) were quantified for integral, trabecular, and cortical bone at the femoral neck, trochanteric, and total proximal femur regions. Changes in bone volumes, cross-sectional areas, and surrogate measures of compressive and bending strength were also determined. During the acute period of SCI, subjects experienced a 2.7-3.3%/month reduction in integral BMC (p < 0.001) and a 2.5-3.1 %/month reduction in integral vBMD (p < 0.001). Trabecular BMC decreased by 3.1-4.7 %/month (p < 0.001) and trabecular vBMD by 2.8-4.4 %/month (p < 0.001). A 3.9-4.0 %/month reduction was observed for cortical BMC (p < 0.001), while the reduction in cortical vBMD was noticeably lower (0.8-1.0 %/month; p ≤ 0.01). Changes in bone volume and cross-sectional area suggested that cortical bone loss occurred primarily through endosteal resorption. Declines in bone mineral were associated with a 4.9-5.9 %/month reduction in surrogate measures of strength. These data highlight the need for therapeutic interventions in this population that target both trabecular and endocortical bone mineral

  9. The combination of structural parameters and areal bone mineral density improves relation to proximal femur strength

    DEFF Research Database (Denmark)

    Hansen, Stinus; Jensen, Jens-Erik Beck; Ahrberg, Fabian

    2011-01-01

    -one human proximal femur specimens (8 men and 23 women, median age 74 years, range 50-89) were examined with HR-pQCT at four regions of interest (femoral head, neck, major and minor trochanter) with 82 μm and in a subgroup (n = 17) with 41 μm resolution. Separate analyses of cortical and trabecular geometry...... fractures were confirmed. Geometry, vBMD, microarchitecture, and aBMD correlated significantly with MCS, with Spearman's correlation coefficients up to 0.77, 0.89, 0.90, and 0.85 (P ...

  10. Mild cognitive impairment, poor episodic memory, and late-life depression are associated with cerebral cortical thinning and increased white matter hyperintensities

    Directory of Open Access Journals (Sweden)

    Motonobu eFujishima

    2014-11-01

    Full Text Available In various independent studies to date, cerebral cortical thickness and white matter hyperintensity (WMH volume have been associated with episodic memory, depression, and mild cognitive impairment (MCI. The aim of this study was to uncover variations in cortical thickness and WMH volume in association with episodic memory, depressive state, and the presence of MCI simultaneously in a single study population. The participants were 186 individuals with MCI (clinical dementia rating [CDR] of 0.5 and 136 healthy elderly controls (HCs; CDR of 0 drawn from two community-based cohort studies in northern Japan. We computed cerebral cortical thickness and WMH volume by using MR scans and statistically analyzed differences in these indices between HCs and MCI participants. We also assessed the associations of these indices with memory performance and depressive state in participants with MCI. Compared with HCs, MCI participants exhibited thinner cortices in the temporal and inferior parietal lobes and greater WMH volumes in the corona radiata and semioval center. In MCI participants, poor episodic memory was associated with thinner cortices in the left entorhinal region and increased WMH volume in the posterior periventricular regions. Compared with non-depressed MCI participants, depressed MCI participants showed reduced cortical thickness in the anterior medial temporal lobe and ambient gyrus adjacent to the amygdala bilaterally, as well as greater WMH volume as a percentage of the total intracranial volume (WMHr. A higher WMHr was associated with cortical thinning in the frontal, temporal, and parietal regions in MCI participants. These results demonstrate that episodic memory and depression are associated with both cortical thickness and WMH volume in MCI participants. Additional longitudinal studies are needed to clarify the dynamic associations and interactions among these indices.

  11. Proximal Alternating Direction Method with Relaxed Proximal Parameters for the Least Squares Covariance Adjustment Problem

    Directory of Open Access Journals (Sweden)

    Minghua Xu

    2014-01-01

    Full Text Available We consider the problem of seeking a symmetric positive semidefinite matrix in a closed convex set to approximate a given matrix. This problem may arise in several areas of numerical linear algebra or come from finance industry or statistics and thus has many applications. For solving this class of matrix optimization problems, many methods have been proposed in the literature. The proximal alternating direction method is one of those methods which can be easily applied to solve these matrix optimization problems. Generally, the proximal parameters of the proximal alternating direction method are greater than zero. In this paper, we conclude that the restriction on the proximal parameters can be relaxed for solving this kind of matrix optimization problems. Numerical experiments also show that the proximal alternating direction method with the relaxed proximal parameters is convergent and generally has a better performance than the classical proximal alternating direction method.

  12. Static and dynamic through thickness lamina properties of thick laminates

    NARCIS (Netherlands)

    Lahuerta, F.; Nijssen, R.P.L.; Van der Meer, F.P.; Sluys, L.J.

    2015-01-01

    Thick laminates are increasingly present in large composites structures such as wind turbine blades. Different factors are suspected to be involved in the decreased static and dynamic performance of thick laminates. These include the effect of self-heating, the scaling effect, and the manufacturing

  13. The Life Saving Effects of Hospital Proximity

    DEFF Research Database (Denmark)

    Bertoli, Paola; Grembi, Veronica

    We assess the lifesaving effect of hospital proximity using data on fatality rates of road-traffic accidents. While most of the literature on this topic is based on changes in distance to the nearest hospital triggered by hospital closures and use OLS estimates, our identification comes from......) increases the fatality rate by 13.84% on the sample average. This is equal to a 0.92 additional death per every 100 accidents. We show that OLS estimates provide a downward biased measure of the real effect of hospital proximity because they do not fully solve spatial sorting problems. Proximity matters...

  14. Pattern of regional cortical thinning associated with cognitive deterioration in Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Javier Pagonabarraga

    Full Text Available BACKGROUND: Dementia is a frequent and devastating complication in Parkinson's disease (PD. There is an intensive search for biomarkers that may predict the progression from normal cognition (PD-NC to dementia (PDD in PD. Mild cognitive impairment in PD (PD-MCI seems to represent a transitional state between PD-NC and PDD. Few studies have explored the structural changes that differentiate PD-NC from PD-MCI and PDD patients. OBJECTIVES AND METHODS: We aimed to analyze changes in cortical thickness on 3.0T Magnetic Resonance Imaging (MRI across stages of cognitive decline in a prospective sample of PD-NC (n = 26, PD-MCI (n = 26 and PDD (n = 20 patients, compared to a group of healthy subjects (HC (n = 18. Cortical thickness measurements were made using the automatic software Freesurfer. RESULTS: In a sample of 72 PD patients, a pattern of linear and progressive cortical thinning was observed between cognitive groups in cortical areas functionally specialized in declarative memory (entorhinal cortex, anterior temporal pole, semantic knowledge (parahippocampus, fusiform gyrus, and visuoperceptive integration (banks of the superior temporal sulcus, lingual gyrus, cuneus and precuneus. Positive correlation was observed between confrontation naming and thinning in the fusiform gyrus, parahippocampal gyrus and anterior temporal pole; clock copy with thinning of the precuneus, parahippocampal and lingual gyrus; and delayed memory with thinning of the bilateral anteromedial temporal cortex. CONCLUSIONS: The pattern of regional decreased cortical thickness that relates to cognitive deterioration is present in PD-MCI patients, involving areas that play a central role in the storage of prior experiences, integration of external perceptions, and semantic processing.

  15. Structural evidence for counter-current flow in proximal tubules versus pertitubular capillaries in the rat kidney. Evaluation of the counter-current mechanism between the proximal convoluted tubules and the peritubular capillaries in the rat nephron

    DEFF Research Database (Denmark)

    Faarup, P; Holstein-Rathlou, N H; Hegedüs, V

    2000-01-01

    BACKGROUND: In spite of the very high exchange of water and solutes between the proximal tubules and the peritubular capillaries, very little is known about flow directions in these two interrelated structures. We therefore developed a morphological technique suitable for the quantitative...... evaluation of a counter-current system between the proximal convoluted tubules and the peritubular capillaries in rat renal cortex. METHODS: In male pentothal-anesthetized Wistar rats (body weight 200-250 g), India ink was injected into the aorta above the renal arteries, followed by instant freezing...... of the right kidney in isopentane at -165 degrees C, and subsequent freeze-substitution in alcohol. In microscopic slides from kidneys in which only 20-55% of the cortical peritubular capillary loops was filled with ink--representing the arterial end of the capillaries--and in which the proximal tubular...

  16. Improving prediction of Alzheimer’s disease using patterns of cortical thinning and homogenizing images according to disease stage

    DEFF Research Database (Denmark)

    Eskildsen, Simon Fristed; Coupé, Pierrick; García-Lorenzo, Daniel

    Predicting Alzheimer’s disease (AD) in individuals with some symptoms of cognitive decline may have great influence on treatment choice and guide subject selection in trials on disease modifying drugs. Structural MRI has the potential of revealing early signs of neurodegeneration in the human brain...... and may thus aid in predicting and diagnosing AD. Surface-based cortical thickness measurements from T1-weighted MRI have demonstrated high sensitivity to cortical gray matter changes. In this study, we investigated the possibility of using patterns of cortical thickness measurements for predicting AD...... of conversion from MCI to AD can be improved by learning the atrophy patterns that are specific to the different stages of disease progression. This has the potential to guide the further development of imaging biomarkers in AD....

  17. Histologic changes in selenite cortical cataract.

    Science.gov (United States)

    Anderson, R S; Trune, D R; Shearer, T R

    1988-09-01

    Massive cortical cataract was produced 15-30 days after a single injection of an overdose of sodium selenite into 14-day-old rats. Most of the cortical cataract appeared to be due to extensive liquefaction of cortical fibers. Water influx, following initial damage to the epithelium by selenium, and action of lens proteases were probable mechanisms for the extensive liquefaction. Remarkably, selenite cortical cataract spontaneously cleared after several months, restoring essentially normal cells to the epithelium and outer and mid-cortex. Major mechanisms for clearing probably involved: (1) removal of damaged proteins from the lens by extensive proteolysis; and (2) replacement of fibers by resumption of normal fibergenesis. The data emphasized the remarkable reparative potential of the lens, and indicated the usefulness of the selenite cortical cataract as a model to study such processes.

  18. Cortical Odor Processing in Health and Disease

    Science.gov (United States)

    Wilson, Donald A.; Xu, Wenjin; Sadrian, Benjamin; Courtiol, Emmanuelle; Cohen, Yaniv; Barnes, Dylan C.

    2014-01-01

    The olfactory system has a rich cortical representation, including a large archicortical component present in most vertebrates, and in mammals neocortical components including the entorhinal and orbitofrontal cortices. Together, these cortical components contribute to normal odor perception and memory. They help transform the physicochemical features of volatile molecules inhaled or exhaled through the nose into the perception of odor objects with rich associative and hedonic aspects. This chapter focuses on how olfactory cortical areas contribute to odor perception and begins to explore why odor perception is so sensitive to disease and pathology. Odor perception is disrupted by a wide range of disorders including Alzheimer’s disease, Parkinson’s disease, schizophrenia, depression, autism, and early life exposure to toxins. This olfactory deficit often occurs despite maintained functioning in other sensory systems. Does the unusual network of olfactory cortical structures contribute to this sensitivity? PMID:24767487

  19. A scale-space curvature matching algorithm for the reconstruction of complex proximal humeral fractures.

    Science.gov (United States)

    Vlachopoulos, Lazaros; Székely, Gábor; Gerber, Christian; Fürnstahl, Philipp

    2018-01-01

    The optimal surgical treatment of complex fractures of the proximal humerus is controversial. It is proven that best results are obtained if an anatomical reduction of the fragments is achieved and, therefore, computer-assisted methods have been proposed for the reconstruction of the fractures. However, complex fractures of the proximal humerus are commonly accompanied with a relevant displacement of the fragments and, therefore, algorithms relying on the initial position of the fragments might fail. The state-of-the-art algorithm for complex fractures of the proximal humerus requires the acquisition of a CT scan of the (healthy) contralateral anatomy as a reconstruction template to address the displacement of the fragments. Pose-invariant fracture line based reconstruction algorithms have been applied successful for reassembling broken vessels in archaeology. Nevertheless, the extraction of the fracture lines and the necessary computation of their curvature are susceptible to noise and make the application of previous approaches difficult or even impossible for bone fractures close to the joints, where the cortical layer is thin. We present a novel scale-space representation of the curvature, permitting to calculate the correct alignment between bone fragments solely based on corresponding regions of the fracture lines. The fractures of the proximal humerus are automatically reconstructed based on iterative pairwise reduction of the fragments. The validation of the presented method was performed on twelve clinical cases, surgically treated after complex proximal humeral fracture, and by cadaver experiments. The accuracy of our approach was compared to the state-of-the-art algorithm for complex fractures of the proximal humerus. All reconstructions of the clinical cases resulted in an accurate approximation of the pre-traumatic anatomy. The accuracy of the reconstructed cadaver cases outperformed the current state-of-the-art algorithm. Copyright © 2017 Elsevier B

  20. Proximal Tubular Injury in Medullary Rays Is an Early Sign of Acute Tacrolimus Nephrotoxicity

    Directory of Open Access Journals (Sweden)

    Diane Cosner

    2015-01-01

    Full Text Available Tacrolimus (FK506 is one of the principal immunosuppressive agents used after solid organ transplantations to prevent allograft rejection. Chronic renal injury induced by tacrolimus is characterized by linear fibrosis in the medullary rays; however, the early morphologic findings of acute tacrolimus nephrotoxicity are not well characterized. Kidney injury molecule-1 (KIM-1 is a specific injury biomarker that has been proven to be useful in the diagnosis of mild to severe acute tubular injury on renal biopsies. This study was motivated by a patient with acute kidney injury associated with elevated serum tacrolimus levels in whom KIM-1 staining was present only in proximal tubules located in the medullary rays in the setting of otherwise normal light, immunofluorescent, and electron microscopy. We subsequently evaluated KIM-1 expression in 45 protocol and 39 indicated renal transplant biopsies to determine whether higher serum levels of tacrolimus were associated with acute segment specific injury to the proximal tubule, as reflected by KIM-1 staining in the proximal tubules of the cortical medullary rays. The data suggest that tacrolimus toxicity preferentially affects proximal tubules in medullary rays and that this targeted injury is a precursor lesion for the linear fibrosis seen in chronic tacrolimus toxicity.

  1. Cortical cartography and Caret software.

    Science.gov (United States)

    Van Essen, David C

    2012-08-15

    Caret software is widely used for analyzing and visualizing many types of fMRI data, often in conjunction with experimental data from other modalities. This article places Caret's development in a historical context that spans three decades of brain mapping--from the early days of manually generated flat maps to the nascent field of human connectomics. It also highlights some of Caret's distinctive capabilities. This includes the ease of visualizing data on surfaces and/or volumes and on atlases as well as individual subjects. Caret can display many types of experimental data using various combinations of overlays (e.g., fMRI activation maps, cortical parcellations, areal boundaries), and it has other features that facilitate the analysis and visualization of complex neuroimaging datasets. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Unsupervised fetal cortical surface parcellation

    Science.gov (United States)

    Dahdouh, Sonia; Limperopoulos, Catherine

    2016-03-01

    At the core of many neuro-imaging studies, atlas-based brain parcellations are used for example to study normal brain evolution across the lifespan. These atlases rely on the assumption that the same anatomical features are present on all subjects to be studied and that these features are stable enough to allow meaningful comparisons between different brain surfaces and structures These methods, however, often fail when applied to fetal MRI data, due to the lack of consistent anatomical features present across gestation. This paper presents a novel surface-based fetal cortical parcellation framework which attempts to circumvent the lack of consistent anatomical features by proposing a brain parcellation scheme that is based solely on learned geometrical features. A mesh signature incorporating both extrinsic and intrinsic geometrical features is proposed and used in a clustering scheme to define a parcellation of the fetal brain. This parcellation is then learned using a Random Forest (RF) based learning approach and then further refined in an alpha-expansion graph-cut scheme. Based on the votes obtained by the RF inference procedure, a probability map is computed and used as a data term in the graph-cut procedure. The smoothness term is defined by learning a transition matrix based on the dihedral angles of the faces. Qualitative and quantitative results on a cohort of both healthy and high-risk fetuses are presented. Both visual and quantitative assessments show good results demonstrating a reliable method for fetal brain data and the possibility of obtaining a parcellation of the fetal cortical surfaces using only geometrical features.

  3. Automatic 3D graph cuts for brain cortex segmentation in patients with focal cortical dysplasia.

    Science.gov (United States)

    Despotović, Ivana; Segers, Ief; Platisa, Ljiljana; Vansteenkiste, Ewout; Pizurica, Aleksandra; Deblaere, Karel; Philips, Wilfried

    2011-01-01

    In patients with intractable epilepsy, focal cortical dysplasia (FCD) is the most frequent malformation of cortical development. Identification of subtle FCD lesions using brain MRI scans is very often based on the cortical thickness measurement, where brain cortex segmentation is required as a preprocessing step. However, the accuracy of the selected segmentation method can highly affect the final FCD lesion detection. In this work, we propose an improved graph cuts algorithm integrating Markov random field-based energy function for more accurate brain cortex MRI segmentation. Our method uses three-label graph cuts and preforms automatic 3D MRI brain cortex segmentation integrating intensity and boundary information. The performance of the method is tested on both simulated MR brain images with different noise levels and real patients with FCD lesions. Experimental quantitative segmentation results showed that the proposed method is effective, robust to noise and achieves higher accuracy than other popular brain MRI segmentation methods. The qualitative validation, visually verified by a medical expert, showed that the FCD lesions were segmented well as a part of the cortex, indicating increased thickness and cortical deformation. The proposed technique can be successfully used in this, as well as in many other clinical applications.

  4. Cortical morphometry in frontoparietal and default mode networks in math-gifted adolescents.

    Science.gov (United States)

    Navas-Sánchez, Francisco J; Carmona, Susana; Alemán-Gómez, Yasser; Sánchez-González, Javier; Guzmán-de-Villoria, Juan; Franco, Carolina; Robles, Olalla; Arango, Celso; Desco, Manuel

    2016-05-01

    Math-gifted subjects are characterized by above-age performance in intelligence tests, exceptional creativity, and high task commitment. Neuroimaging studies reveal enhanced functional brain organization and white matter microstructure in the frontoparietal executive network of math-gifted individuals. However, the cortical morphometry of these subjects remains largely unknown. The main goal of this study was to compare the cortical morphometry of math-gifted adolescents with that of an age- and IQ-matched control group. We used surface-based methods to perform a vertex-wise analysis of cortical thickness and surface area. Our results show that math-gifted adolescents present a thinner cortex and a larger surface area in key regions of the frontoparietal and default mode networks, which are involved in executive processing and creative thinking, respectively. The combination of reduced cortical thickness and larger surface area suggests above-age neural maturation of these networks in math-gifted individuals. Hum Brain Mapp 37:1893-1902, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Proximity and Collaboration in European Nanotechnology

    NARCIS (Netherlands)

    Cunningham, S.W.; Werker, C.

    2011-01-01

    Collaborations are particularly important for the development and deployment of technology. We analyze the influence of organizational, technological and geographical proximity on European nanotechnology collaborations with the help of a publication dataset and additional geographical information.

  6. Promoting proximal formative assessment with relational discourse

    Science.gov (United States)

    Scherr, Rachel E.; Close, Hunter G.; McKagan, Sarah B.

    2012-02-01

    The practice of proximal formative assessment - the continual, responsive attention to students' developing understanding as it is expressed in real time - depends on students' sharing their ideas with instructors and on teachers' attending to them. Rogerian psychology presents an account of the conditions under which proximal formative assessment may be promoted or inhibited: (1) Normal classroom conditions, characterized by evaluation and attention to learning targets, may present threats to students' sense of their own competence and value, causing them to conceal their ideas and reducing the potential for proximal formative assessment. (2) In contrast, discourse patterns characterized by positive anticipation and attention to learner ideas increase the potential for proximal formative assessment and promote self-directed learning. We present an analysis methodology based on these principles and demonstrate its utility for understanding episodes of university physics instruction.

  7. Ammonia transport in the proximal tubule.

    Science.gov (United States)

    Hamm, L L; Simon, E E

    1990-01-01

    The transport of ammonia in the proximal tubule is a complex interaction of a number of processes. Ammonia transport in the proximal tubule is clearly bidirectional; ammonia is secreted into the early proximal tubule lumen, but later in the proximal tubule, efflux out of the lumen may result in net ammonia reabsorption. Two mechanisms of ammonia transport have clearly been established: NH3 diffusion and NH4+ transport on the Na(+)-H+ exchanger. The relative contribution of these pathways to ammonia transport is still unsettled. Other pathways for ammonia transport, particularly NH4+ efflux out of the lumen, may be important as well. A variety of factors may modulate ammonia transport: plasma, cell and luminal pH, luminal flow rate, luminal potassium, and angiotensin II. Each of these factors also alters ammonia production rates and in most circumstances, ammonia transport appears to follow ammonia production rates.

  8. Proximate composition and cholesterol concentrations of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    DWB) for raw and fried samples, respectively, but decreased to 295.20 ... Key words: Rhynchophorus phoenicis, Oryctes monoceros, proximate composition, cholesterol, heat treatment. INTRODUCTION. Insects have played ...

  9. COMPARATIVE ANALYSIS OF PROXIMATE COMPOSITIONS OF ...

    African Journals Online (AJOL)

    Babatunde Emmanuel

    2011-10-06

    Oct 6, 2011 ... Fish allows for protein improved nutrition in that it has a high biological value in terms of high ... marine algae upon which the fish feed [11]. ... Proximate composition of catfish Clarias gariepinus and Tarpon atlanticus were.

  10. Deltoid Tuberosity Index: A Simple Radiographic Tool to Assess Local Bone Quality in Proximal Humerus Fractures.

    Science.gov (United States)

    Spross, Christian; Kaestle, Nicola; Benninger, Emanuel; Fornaro, Jürgen; Erhardt, Johannes; Zdravkovic, Vilijam; Jost, Bernhard

    2015-09-01

    Osteoporosis may complicate surgical fixation and healing of proximal humerus fractures and should be assessed preoperatively. Peripheral quantitative CT (pQCT) and the Tingart measurement are helpful methods, but both have limitations in clinical use because of limited availability (pQCT) or fracture lines crossing the area of interest (Tingart measurement). The aim of our study was to introduce and validate a simple cortical index to assess the quality of bone in proximal humerus fractures using AP radiographs. We asked: (1) How do the deltoid tuberosity index and Tingart measurement correlate with each other, with patient age, and local bone mineral density (BMD) of the humeral head, measured by pQCT? (2) Which threshold values for the deltoid tuberosity index and Tingart measurement optimally discriminate poor local bone quality of the proximal humerus? (3) Are the deltoid tuberosity index and Tingart measurement clinically applicable and reproducible in patients with proximal humerus fractures? The deltoid tuberosity index was measured immediately above the upper end of the deltoid tuberosity. At this position, where the outer cortical borders become parallel, the deltoid tuberosity index equals the ratio between the outer cortical and inner endosteal diameter. In the first part of our study, we retrospectively measured the deltoid tuberosity index on 31 patients (16 women, 15 men; mean age, 65 years; range, 22-83 years) who were scheduled for elective surgery other than fracture repair. Inclusion criteria were available native pQCT scans, AP shoulder radiographs taken in internal rotation, and no previous shoulder surgery. The deltoid tuberosity index and the Tingart measurement were measured on the preoperative internal rotation AP radiograph. The second part of our study was performed by reviewing 40 radiographs of patients with proximal humerus fractures (31 women, nine men; median age, 65 years; range, 22-88 years). Interrater (two surgeons) and

  11. Detecting Alzheimer’s disease by morphological MRI using hippocampal grading and cortical thickness

    DEFF Research Database (Denmark)

    Eskildsen, Simon Fristed; Coupé, Pierrick; Fonov, Vladimir

    2014-01-01

    Structural MRI is an important imaging biomarker in Alzheimer’s disease as the cerebral atrophy has been shown to closely correlate with cogni-tive symptoms. Recognizing this, numerous methods have been developed for quantifying the disease related atrophy from MRI over the past decades. Special...... validation frameworks. To address this issue, the public challenge on Computer-Aided Di-agnosis of Dementia based on structural MRI data (CADDementia) was pro-posed. The challenge calls for accurate classification of 354 MRI scans collect-ed among AD patients, subjects with mild cognitive impairment...... effort has been dedicated to separate AD related modifications from normal ag-ing for the purpose of early detection and prediction. Several groups have re-ported promising results using automatic methods; however, it is very difficult to compare these methods due to varying cohorts and different...

  12. Age-related changes in cortical bone thickness of ancient Egyptians

    Directory of Open Access Journals (Sweden)

    Moushira Erfan Zaki

    2016-06-01

    Conclusions: The present results highlight important sex-specific differences in patterns of age-related bone loss. These findings are comparable to those from other human populations and represent a valid resource for clinical application and for comparisons with contemporary subjects.

  13. Impaired response inhibition and excess cortical thickness as candidate endophenotypes for trichotillomania

    DEFF Research Database (Denmark)

    Odlaug, Brian Lawrence; Chamberlain, Samuel R; Derbyshire, Katie L

    2014-01-01

    Trichotillomania is characterized by repetitive pulling out of one's own hair. Impaired response inhibition has been identified in patients with trichotillomania, along with gray matter density changes in distributed neural regions including frontal cortex. The objective of this study...

  14. Immunometabolic dysregulation is associated with reduced cortical thickness of the anterior cingulate cortex

    NARCIS (Netherlands)

    van Velzen, Laura S.; Schmaal, Lianne; Milaneschi, Yuri; van Tol, Marie-Jose; van der Wee, Nic J. A.; Veltman, Dick. J.; Penninx, Brenda W. J. H.

    Background: Immunometabolic dysregulation (low-grade inflammation and metabolic dysregulation) has been associated with the onset and more severe course of multiple psychiatric disorders, partly due to neuroanatomical changes and impaired neuroplasticity. We examined the effect of multiple markers

  15. Reduced Cortical Thickness as an Outcome of Differential Sensitivity to Environmental Risks in Schizophrenia

    NARCIS (Netherlands)

    Habets, Petra; Marcelis, Machteld; Gronenschild, Ed; Drukker, Marian; van Os, Jim

    2011-01-01

    Background: The etiology of schizophrenia is thought to involve differential likely genetically mediated sensitivity to environmental exposures. However, examination of differential sensitivity in models of psychopathologic constructs is subject to bias because psychopathology itself may distort

  16. Reduced cortical thickness as an outcome of differential sensitivity to environmental risks in schizophrenia

    NARCIS (Netherlands)

    Habets, Petra; Marcelis, Machteld; Gronenschild, Ed; Drukker, Marjan; van Os, Jim; Kahn, René S.; Linszen, Don H.; Wiersma, Durk; Bruggerman, Richard; Cahn, Wiepke; de Haan, Lieuwe; Krabbendam, Lydia; Myin-Germeys, Inez

    2011-01-01

    The etiology of schizophrenia is thought to involve differential-likely genetically mediated-sensitivity to environmental exposures. However, examination of differential sensitivity in models of psychopathologic constructs is subject to bias because psychopathology itself may distort exposure

  17. Phytochemical screening, proximate analysis and acute toxicity ...

    African Journals Online (AJOL)

    Phytochemical screening, proximate analysis and acute toxicity studies were carried out on the leaf extract of Cola lepidota, in accordance with established standard procedures. The proximate analysis reveals a moisture content of 27.43 ± 3.11 % w/w, total ash value 9.32 ± 0.27 % w/w, acid insoluble ash 3.12 ± 1.05 % w/w ...

  18. Proximate, Mineral and Phytochemical Composition of Dioscorea ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT: Proximate, mineral and phytochemical composition of Dioscorea dumetorum tubers was investigated using standard procedures. Proximate analysis included in g% dry weight: crude protein (6.44 ± 0.32), crude fat (0.75 ± 0.04), crude fibre (15.00 ± 0.56), total ash. (3.45 ± 0.20) and a moisture content of 70.04 ...

  19. Painful Spastic Hip Dislocation: Proximal Femoral Resection

    OpenAIRE

    Albiñana, Javier; Gonzalez-Moran, Gaspar

    2002-01-01

    The dislocated hip in a non-ambulatory child with spastic paresis tends to be a painful interference to sleep, sitting upright, and perineal care. Proximal femoral resection-interposition arthroplasty is one method of treatment for this condition. We reviewed eight hips, two bilateral cases, with a mean follow-up of 30 months. Clinical improvement was observed in all except one case, with respect to pain relief and sitting tolerance. Some proximal migration was observed in three cases, despit...

  20. Cortical morphometry and cognition in very preterm and term-born children at early school age.

    Science.gov (United States)

    Mürner-Lavanchy, Ines; Rummel, Christian; Steinlin, Maja; Everts, Regula

    2018-01-01

    Very preterm birth influences brain development and may result in alterations of cortical morphometry. These structural alterations may interact with cognitive development. The aim of the present study was to investigate the structure-function relationship in school-aged very preterm and term-born control children. A comprehensive neuropsychological test battery was administered to 41 very preterm (preterm children>controls). No group differences occurred for cortical surface area. The relationship between cortical morphometry and cognition differed between very preterm and control children. In very preterm children, some cognitive domains correlated positively and others negatively with regional cortical thickness and cortical surface area. Our findings contribute to the understanding of the structure-function relationship in very preterm children and their term-born peers. They add to the notion that this relationship varies depending on the brain region and the cognitive function in question and suggest developmental differences between very preterm and term-born children. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Language Ability Predicts Cortical Structure and Covariance in Boys with Autism Spectrum Disorder.

    Science.gov (United States)

    Sharda, Megha; Foster, Nicholas E V; Tryfon, Ana; Doyle-Thomas, Krissy A R; Ouimet, Tia; Anagnostou, Evdokia; Evans, Alan C; Zwaigenbaum, Lonnie; Lerch, Jason P; Lewis, John D; Hyde, Krista L

    2017-03-01

    There is significant clinical heterogeneity in language and communication abilities of individuals with Autism Spectrum Disorders (ASD). However, no consistent pathology regarding the relationship of these abilities to brain structure has emerged. Recent developments in anatomical correlation-based approaches to map structural covariance networks (SCNs), combined with detailed behavioral characterization, offer an alternative for studying these relationships. In this study, such an approach was used to study the integrity of SCNs of cortical thickness and surface area associated with language and communication, in 46 high-functioning, school-age children with ASD compared with 50 matched, typically developing controls (all males) with IQ > 75. Findings showed that there was alteration of cortical structure and disruption of fronto-temporal cortical covariance in ASD compared with controls. Furthermore, in an analysis of a subset of ASD participants, alterations in both cortical structure and covariance were modulated by structural language ability of the participants, but not communicative function. These findings indicate that structural language abilities are related to altered fronto-temporal cortical covariance in ASD, much more than symptom severity or cognitive ability. They also support the importance of better characterizing ASD samples while studying brain structure and for better understanding individual differences in language and communication abilities in ASD. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Evidence for cortical structural plasticity in humans after a day of waking and sleep deprivation.

    Science.gov (United States)

    Elvsåshagen, Torbjørn; Zak, Nathalia; Norbom, Linn B; Pedersen, Per Ø; Quraishi, Sophia H; Bjørnerud, Atle; Alnæs, Dag; Doan, Nhat Trung; Malt, Ulrik F; Groote, Inge R; Westlye, Lars T

    2017-08-01

    Sleep is an evolutionarily conserved process required for human health and functioning. Insufficient sleep causes impairments across cognitive domains, and sleep deprivation can have rapid antidepressive effects in mood disorders. However, the neurobiological effects of waking and sleep are not well understood. Recently, animal studies indicated that waking and sleep are associated with substantial cortical structural plasticity. Here, we hypothesized that structural plasticity can be observed after a day of waking and sleep deprivation in the human cerebral cortex. To test this hypothesis, 61 healthy adult males underwent structural magnetic resonance imaging (MRI) at three time points: in the morning after a regular night's sleep, the evening of the same day, and the next morning, either after total sleep deprivation (N=41) or a night of sleep (N=20). We found significantly increased right prefrontal cortical thickness from morning to evening across all participants. In addition, pairwise comparisons in the deprived group between the two morning scans showed significant thinning of mainly bilateral medial parietal cortices after 23h of sleep deprivation, including the precuneus and posterior cingulate cortex. However, there were no significant group (sleep vs. sleep deprived group) by time interactions and we can therefore not rule out that other mechanisms than sleep deprivation per se underlie the bilateral medial parietal cortical thinning observed in the deprived group. Nonetheless, these cortices are thought to subserve wakefulness, are among the brain regions with highest metabolic rate during wake, and are considered some of the most sensitive cortical regions to a variety of insults. Furthermore, greater thinning within the left medial parietal cluster was associated with increased sleepiness after sleep deprivation. Together, these findings add to a growing body of data showing rapid structural plasticity within the human cerebral cortex detectable with

  3. Tuning the Proximity Effect through Interface Engineering in a Pb/Graphene/Pt Trilayer System.

    Science.gov (United States)

    Fei, Xiangmin; Xiao, Wende; Yang, Kai; Liu, Liwei; Pan, Jinbo; Chen, Hui; Zhang, Chendong; Shih, Chih-Kang; Du, Shixuan; Gao, Hongjun

    2016-04-26

    The fate of superconductivity of a nanoscale superconducting film/island relies on the environment; for example, the proximity effect from the substrate plays a crucial role when the film thicknesses is much less than the coherent length. Here, we demonstrate that atomic-scale tuning of the proximity effects can be achieved by one atomically thin graphene layer inserted between the nanoscale Pb islands and the supporting Pt(111) substrate. By using scanning tunneling microscopy and spectroscopy, we show that the coupling between the electron in a normal metal and the Cooper pair in an adjacent superconductor is dampened by 1 order of magnitude via transmission through a single-atom-thick graphene. More interestingly, the superconductivity of the Pb islands is greatly affected by the moiré patterns of graphene, showing the intriguing influence of the graphene-substrate coupling on the superconducting properties of the overlayer.

  4. Proximity sensor system development. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Haley, D.C. [Oak Ridge National Lab., TN (United States); Pigoski, T.M. [Merrit Systems, Inc. (United States)

    1998-01-01

    Lockheed Martin Energy Research Corporation (LMERC) and Merritt Systems, Inc. (MSI) entered into a Cooperative Research and Development Agreement (CRADA) for the development and demonstration of a compact, modular proximity sensing system suitable for application to a wide class of manipulator systems operated in support of environmental restoration and waste management activities. In teleoperated modes, proximity sensing provides the manipulator operator continuous information regarding the proximity of the manipulator to objects in the workspace. In teleoperated and robotic modes, proximity sensing provides added safety through the implementation of active whole arm collision avoidance capabilities. Oak Ridge National Laboratory (ORNL), managed by LMERC for the United States Department of Energy (DOE), has developed an application specific integrated circuit (ASIC) design for the electronics required to support a modular whole arm proximity sensing system based on the use of capacitive sensors developed at Sandia National Laboratories. The use of ASIC technology greatly reduces the size of the electronics required to support the selected sensor types allowing deployment of many small sensor nodes over a large area of the manipulator surface to provide maximum sensor coverage. The ASIC design also provides a communication interface to support sensor commands from and sensor data transmission to a distributed processing system which allows modular implementation and operation of the sensor system. MSI is a commercial small business specializing in proximity sensing systems based upon infrared and acoustic sensors.

  5. Transformations through Proximity Flying: A Phenomenological Investigation

    Science.gov (United States)

    Holmbom, Maria; Brymer, Eric; Schweitzer, Robert D.

    2017-01-01

    Participation in extreme sports has been linked to personal transformations in everyday life. Descriptions of lived experience resulting from transformative experiences are limited. Proximity flying, a relatively new discipline involving BASE jumping with a wingsuit where participants fly close to solid structures, is arguably one of the most extreme of extreme sports. The aim of this paper, part of a larger phenomenological study on the lived experience of proximity flying, is to explicate the ways in which participating in proximity flying influences the everyday lives of participants. Interpretative phenomenological analysis was used to explicate the lived experience of six proximity pilots. An analysis of interview transcripts revealed three significant themes describing the lived experience of participants. First, experiences of change were described as positive and skills developed through proximity flying were transferable into everyday life. Second, transformative experiences were considered fundamental to participants’ perspectives on life. Third, experience of transformation influenced their sense of personal identity and facilitated flourishing in other aspects of everyday life. Participants were clear that their experiences in proximity flying facilitated a profound process of transformation which manifest as changes in everyday capabilities and behaviors, values and sense of identity. PMID:29104552

  6. Cortical atrophy in patients with cerebral amyloid angiopathy: a case-control study.

    Science.gov (United States)

    Fotiadis, Panagiotis; van Rooden, Sanneke; van der Grond, Jeroen; Schultz, Aaron; Martinez-Ramirez, Sergi; Auriel, Eitan; Reijmer, Yael; van Opstal, Anna M; Ayres, Alison; Schwab, Kristin M; Hedden, Trey; Rosand, Jonathan; Viswanathan, Anand; Wermer, Marieke; Terwindt, Gisela; Sperling, Reisa A; Polimeni, Jonathan R; Johnson, Keith A; van Buchem, Mark A; Greenberg, Steven M; Gurol, M Edip

    2016-07-01

    Loss of cortical grey matter is a diagnostic marker of many neurodegenerative diseases, and is a key mediator of cognitive impairment. We postulated that cerebral amyloid angiopathy (CAA), characterised by cortical vascular amyloid deposits, is associated with cortical tissue loss independent of parenchymal Alzheimer's disease pathology. We tested this hypothesis in patients with hereditary cerebral haemorrhage with amyloidosis-Dutch type (HCHWA-D), a monogenetic disease with minimal or no concomitant Alzheimer's disease pathology, as well as in patients with sporadic CAA and healthy and Alzheimer's disease controls. In this observational case-control study, we included six groups of participants: patients diagnosed with HCHWA-D using genetic testing; healthy controls age-matched to the HCHWA-D group; patients with probable sporadic CAA without dementia; two independent cohorts of healthy controls age-matched to the CAA group; and patients with Alzheimer's disease age-matched to the CAA group. De-identified (but unmasked) demographic, clinical, radiological, and genetic data were collected at Massachusetts General Hospital (Boston, MA, USA), at Leiden University (Leiden, Netherlands), and at sites contributing to Alzheimer's Disease Neuroimaging Initiative (ADNI). The primary outcome measure was cortical thickness. The correlations between cortical thickness and structural lesions, and blood-oxygen-level-dependent time-to-peak (BOLD-TTP; a physiological measure of vascular dysfunction) were analysed to understand the potential mechanistic link between vascular amyloid and cortical thickness. The radiological variables of interest were quantified using previously validated computer-assisted tools, and all results were visually reviewed to ensure their accuracy. Between March 15, 2006, and Dec 1, 2014, we recruited 369 individuals (26 patients with HCHWA-D and 28 age-matched, healthy controls; 63 patients with sporadic CAA without dementia; two healthy control

  7. A peripheral epigenetic signature of immune system genes is linked to neocortical thickness and memory

    Science.gov (United States)

    Freytag, Virginie; Carrillo-Roa, Tania; Milnik, Annette; Sämann, Philipp G.; Vukojevic, Vanja; Coynel, David; Demougin, Philippe; Egli, Tobias; Gschwind, Leo; Jessen, Frank; Loos, Eva; Maier, Wolfgang; Riedel-Heller, Steffi G.; Scherer, Martin; Vogler, Christian; Wagner, Michael; Binder, Elisabeth B.; de Quervain, Dominique J. -F.; Papassotiropoulos, Andreas

    2017-01-01

    Increasing age is tightly linked to decreased thickness of the human neocortex. The biological mechanisms that mediate this effect are hitherto unknown. The DNA methylome, as part of the epigenome, contributes significantly to age-related phenotypic changes. Here, we identify an epigenetic signature that is associated with cortical thickness (P=3.86 × 10−8) and memory performance in 533 healthy young adults. The epigenetic effect on cortical thickness was replicated in a sample comprising 596 participants with major depressive disorder and healthy controls. The epigenetic signature mediates partially the effect of age on cortical thickness (P<0.001). A multilocus genetic score reflecting genetic variability of this signature is associated with memory performance (P=0.0003) in 3,346 young and elderly healthy adults. The genomic location of the contributing methylation sites points to the involvement of specific immune system genes. The decomposition of blood methylome-wide patterns bears considerable potential for the study of brain-related traits. PMID:28443631

  8. Proximity effect in superconductor-insulator-superconductor Josephson tunnel junctions: Theory and experiment

    Science.gov (United States)

    Golubov, A. A.; Houwman, E. P.; Gijsbertsen, J. G.; Krasnov, V. M.; Flokstra, J.; Rogalla, H.; Kupriyanov, M. Yu.

    1995-01-01

    A microscopic model of the proximity effect in superconductor-insulator-superconductor (SS'IS''S) Josephson tunnel junctions has been developed for the general case of the finite critical temperature of the S' (S'') metal, arbitrary SS' (SS'') boundary transparency and the strength of the proximity effect between S and S' (respectively S and S''). The metals are assumed to be in the dirty limit and the thickness of the proximity layer is assumed to be small compared to its coherence length. The electrical properties of the SS'IS''S junction are calculated as a function of the strength of the proximity effect, boundary transparency, critical temperature ratio, and temperature. The experimentally determined electrical characteristics of a series of Nb/Al1, Al oxide, Al2/Nb junctions with varying thickness d1 of the Al1 layer were interpreted with this model. The current-voltage characteristics and the temperature dependence of the critical current and sum-gap voltage could be described quantitatively well without any other correction than the non-BCS ratio Δ0/kBTc~=1.93 of Nb. Deviations from the model for the junctions with the largest d1 are attributed to the fact that the Nb and Al are not fully in the dirty limit and d1 is not small compared to the coherence length.

  9. Encoding Cortical Dynamics in Sparse Features

    Directory of Open Access Journals (Sweden)

    Sheraz eKhan

    2014-05-01

    Full Text Available Distributed cortical solutions of magnetoencephalography (MEG and electroencephalography (EEG exhibit complex spatial and temporal dynamics. The extraction of patterns of interest and dynamic features from these cortical signals has so far relied on the expertise of investigators. There is a definite need in both clinical and neuroscience research for a method that will extract critical features from high-dimensional neuroimaging data in an automatic fashion. We have previously demonstrated the use of optical flow techniques for evaluating the kinematic properties of motion field projected on non-flat manifolds like in a cortical surface. We have further extended this framework to automatically detect features in the optical flow vector field by using the modified and extended 2-Riemannian Helmholtz Hodge Decomposition (HHD. Here, we applied these mathematical models on simulation and MEG data recorded from a healthy individual during a somatosensory experiment and an epilepsy pediatric patient during sleep. We tested whether our technique can automatically extract salient dynamical features of cortical activity. Simulation results indicated that we can precisely reproduce the simulated cortical dynamics with HHD; encode them in sparse features and represent the propagation of brain activity between distinct cortical areas. Using HHD, we decoded the somatosensory N20 component into two HHD features and represented the dynamics of brain activity as a traveling source between two primary somatosensory regions. In the epilepsy patient, we displayed the propagation of the epileptiform activity around the margins of a brain lesion. Our findings indicate that HHD measures computed from cortical dynamics can: (i quantitatively access the cortical dynamics in both healthy and disease brain in terms of sparse features and dynamic brain activity propagation between distinct cortical areas, and (ii facilitate a reproducible, automated analysis of MEG

  10. Treatment of three- and four-part proximal humeral fractures with locking proximal humerus plate.

    Science.gov (United States)

    Sun, Jing-Cheng; Li, Yu-Lin; Ning, Guang-Zhi; Wu, Qiang; Feng, Shi-Qing

    2013-08-01

    The purpose of this study was to evaluate the effectiveness and complications of the locking proximal humerus plate to treat proximal humerus fractures. A retrospective clinical trial. Department of Orthopaedics, Tianjin Medical University General Hospital. Sixty-eight consecutive patients with three- or four-part fractures of the proximal humerus were treated with locking proximal humerus plates. The deltopectoral anterolateral acromial approach was used to the proximal humerus; open reduction and locking proximal humerus plate were applied. Constant Score was used to measure the shoulder functional recovery, and Visual Analog Scale (VAS) was used to measure subjective evaluation of pain. The radiology was observed. After average 26.7 months, the average Constant Score was 72.6 ± 13.2 points and the average VAS was 1.2 ± 0.8 points. All the complications such as screw perforation into the glenohumeral joint, screws loosening, soft tissue infections, avascular necrosis and delayed union occurred in eight cases (11.8 %). The effectiveness of the locking proximal humerus plate was similar to other published literatures on treating fractures of the proximal humerus; however, a lower complications rate in short follow-up time was observed in this study. It may potentially provide a favorable option for treating three- or four-part fractures of the proximal humerus. Dealing with each particular fracture pattern, surgeons should have a decision of appropriate way to internal fixation.

  11. Tibial cortical lesions: A multimodality pictorial review

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, P.A., E-mail: philippa.tyler@rnoh.nhs.uk [Department of Radiology, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP (United Kingdom); Mohaghegh, P., E-mail: pegah1000@gmail.com [Department of Radiology, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP (United Kingdom); Foley, J., E-mail: jfoley1@nhs.net [Department of Radiology, Glasgow Royal Infirmary, 16 Alexandra Parade, Glasgow G31 2ES (United Kingdom); Isaac, A., E-mail: amandaisaac@doctors.org.uk [Department of Radiology, King' s College Hospital, Denmark Hill, London SE5 9RS (United Kingdom); Zavareh, A., E-mail: ali.zavareh@gmail.com [Department of Radiology, North Bristol NHS Trust, Frenchay, Bristol BS16 1LE (United Kingdom); Thorning, C., E-mail: cthorning@doctors.org.uk [Department of Radiology, East Surrey Hospital, Canada Avenue, Redhill, Surrey RH1 5RH (United Kingdom); Kirwadi, A., E-mail: anandkirwadi@gmail.com [Department of Radiology, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL (United Kingdom); Pressney, I., E-mail: ipressney@hotmail.com [Department of Radiology, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP (United Kingdom); Amary, F., E-mail: fernanda.amary@rnoh.nhs.uk [Department of Histopathology, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP (United Kingdom); Rajeswaran, G., E-mail: grajeswaran@gmail.com [Department of Radiology, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH (United Kingdom)

    2015-01-15

    Highlights: • Multimodality imaging plays an important role in the investigation and diagnosis of shin pain. • We review the multimodality imaging findings of common cortically based tibial lesions. • We also describe the rarer pathologies of tibial cortical lesions. - Abstract: Shin pain is a common complaint, particularly in young and active patients, with a wide range of potential diagnoses and resulting implications. We review the natural history and multimodality imaging findings of the more common causes of cortically-based tibial lesions, as well as the rarer pathologies less frequently encountered in a general radiology department.

  12. Cortical bone density is normal in prepubertal children with growth hormone (GH) deficiency, but initially decreases during GH replacement due to early bone remodeling.

    Science.gov (United States)

    Schweizer, R; Martin, D D; Schwarze, C P; Binder, G; Georgiadou, A; Ihle, J; Ranke, M B

    2003-11-01

    Dual energy x-ray absorptiometry (DEXA) has revealed that GH- deficient adults gain in bone mineral density during GH therapy. Measurements of volumetric bone density (grams per cubic centimeter vs. grams per square centimeter) and structure, however, are achieved through peripheral quantitative computed tomography (pQCT). In 45 prepubertal GH-deficient children, we studied pQCT measurements before the start and for 12 months of GH treatment. Serum alkaline phosphatase (AP), procollagen I carboxyl-terminal propeptide (PICP), and deoxypyridinoline reflected bone metabolism status. Findings at the start of GH treatment were (mean SD score): bone area, -0.44; cortical density, -0.03; cortical area, -1.32; cortical thickness, -1.41; and marrow area, +0.66. At 12 months, cortical density had fallen to -0.73 (P < 0.001), whereas cortical area and thickness, and marrow area did not change. AP, PICP, and deoxypyridinoline increased significantly within the first 3 months (increase: AP, 66.5 U/liter; PICP, 72 microg/liter; DPD, 11.4 nmol/mmol creatinine). The pQCT showed that cortical density is not reduced in GH-deficient patients. Higher bone metabolism explains the lower cortical density after GH therapy commenced. Thus, the manifestation of GH deficiency is evidently similar in children and adults, and pQCT provides important information in addition to DEXA measurements, as DEXA does not take bone structure into account.

  13. Heterozygous deletion of both sclerostin (Sost) and connexin43 (Gja1) genes in mice is not sufficient to impair cortical bone modeling.

    Science.gov (United States)

    Grimston, Susan K; Fontana, Francesca; Watkins, Marcus; Civitelli, Roberto

    2017-01-01

    Connexin43 (Cx43) is the main gap junction protein expressed in bone forming cells, where it modulates peak bone mass acquisition and cortical modeling. Genetic ablation of the Cx43 gene (Gja1) results in cortical expansion with accentuated periosteal bone formation associated with decreased expression of the Wnt inhibitor sclerostin. To determine whether sclerostin (Sost) down-regulation might contribute to periosteal expansion in Gja1 deficient bones, we took a gene interaction approach and crossed mice harboring germline null alleles for Gja1 or Sost to generate single Gja1+/-and Sost+/-and double Gja1+/-;Sost+/-heterozygous mice. In vivo μCT analysis of cortical bone at age 1 and 3 months confirmed increased thickness in Sost-/-mice, but revealed no cortical abnormalities in single Gja1+/-or Sost+/-mice. Double heterozygous Gja1+/-Sost+/-also showed no differences in mineral density, cortical thickness, width or geometry relative to wild type control mice. Likewise, 3-point bending measurement of bone strength revealed no significant differences between double Gja1+/-;Sost+/-or single heterozygous and wild type mice. Although these data do not exclude a contribution of reduced sclerostin in the cortical expansion seen in Gja1 deficient bones, they are not consistent with a strong genetic interaction between Sost and Gja1 dictating cortical modeling.

  14. Gross anatomical and dimensional characteristics of the proximal hamstring origin.

    Science.gov (United States)

    Feucht, Matthias J; Plath, Johannes E; Seppel, Gernot; Hinterwimmer, Stefan; Imhoff, Andreas B; Brucker, Peter U

    2015-09-01

    The current study was undertaken to better define the gross anatomical and dimensional characteristics of the proximal hamstring origin. Twelve paired whole-lower extremities from six embalmed cadavers were dissected. The gross anatomy of the proximal hamstrings was studied. With the tendons attached to the ischial tuberosity, the width and thickness of each tendon was measured 1 cm distally to their origin, and the distance from the most proximal border of the common origin of the semitendinosus (ST) and long head of the biceps (LB) to their distal junction was assessed. After removal of the hamstring group, the shape, orientation, and dimension of the tendon footprints were determined. One cadaver demonstrated unique anatomy, which was considered as an anatomic variant and was therefore excluded from the study group. The ST and LB had a common origin on the posterolateral aspect of the ischial tuberosity (ST/LB), whereas the semimembranosus (SM) had a separated origin at the anterolateral aspect. The mean distance from the most proximal border of the ST/LB origin to the distal junction was 10.0 ± 1.3 cm. The shape of both footprints was longitudinal-oval, with the longitudinal axes of the SM and ST/LB footprints parallel aligned. Mean tendon width was 3.4 ± 0.5 cm for the common ST/LB complex and 4.2 ± 0.9 cm for the SM (p = 0.009). The corresponding values for tendon thickness were 1.0 ± 0.3 cm (ST/LB) and 0.8 ± 0.2 cm (SM), respectively (n.s.). Mean footprint length was 3.9 ± 0.4 cm for ST/LB and 4.5 ± 0.5 cm for SM (p = 0.002). The corresponding values for footprint height were 1.4 ± 0.5 cm (ST/LB) and 1.2 ± 0.3 cm (SM), respectively (n.s.). The ST and LB had a common origin, whereas the SM originated separately. The site of origin of both tendons was the lateral aspect of the ischial tuberosity, with the SM footprint lying directly anterior to the footprint of the ST/LB complex. The footprint of the SM was significantly wider than the footprint of

  15. Pinning technique for shoulder fractures in adolescents: computer modelling of percutaneous pinning of proximal humeral fractures

    Science.gov (United States)

    Mehin, Ramin; Mehin, Afshin; Wickham, David; Letts, Merv

    2009-01-01

    Background In the technique of percuatenous pinning of proximal humerus fractures, the appropriate entry site and trajectory of pins is unknown, especially in the adolescent population. We sought to determine the ideal entry site and trajectory of pins. Methods We used magnetic resonance images of nonfractured shoulders in conjunction with radiographs of shoulder fractures that were treated with closed reduction and pinning to construct 3-dimensional computer-generated models. We used engineering software to determine the ideal location of pins. We also conducted a literature review. Results The nonfractured adolescent shoulder has an articular surface diameter of 41.3 mm, articular surface thickness of 17.4 mm and neck shaft angle of 36°. Although adolescents and adults have relatively similar shoulder skeletal anatomy, they suffer different types of fractures. In our study, 14 of 16 adolescents suffered Salter–Harris type II fractures. The ideal location for the lateral 2 pins in an anatomically reduced shoulder fracture is 4.4 cm and 8.0 cm from the proximal part of the humeral head directed at 21.2° in the coronal plane relative to the humeral shaft. Conclusion Operative management of proximal humerus fractures in adolescents requires knowledge distinct from that required for adult patients. This is the first study to examine the anatomy of the nonfractured proximal humerus in adolescents. This is also the first study to attempt to model the positioning of percutaneous proximal humerus pins. PMID:20011155

  16. Locking plate fixation for proximal humerus fractures.

    LENUS (Irish Health Repository)

    Burke, Neil G

    2012-02-01

    Locking plates are increasingly used to surgically treat proximal humerus fractures. Knowledge of the bone quality of the proximal humerus is important. Studies have shown the medial and dorsal aspects of the proximal humeral head to have the highest bone strength, and this should be exploited by fixation techniques, particularly in elderly patients with osteoporosis. The goals of surgery for proximal humeral fractures should involve minimal soft tissue dissection and achieve anatomic reduction of the head complex with sufficient stability to allow for early shoulder mobilization. This article reviews various treatment options, in particular locking plate fixation. Locking plate fixation is associated with a high complication rate, such as avascular necrosis (7.9%), screw cutout (11.6%), and revision surgery (13.7%). These complications are frequently due to the varus deformation of the humeral head. Strategic screw placement in the humeral head would minimize the possibility of loss of fracture reduction and potential hardware complications. Locking plate fixation is a good surgical option for the management of proximal humerus fractures. Complications can be avoided by using better bone stock and by careful screw placement in the humeral head.

  17. A Digital Stereomicroscopic Study of the Radicular Wall Thickness of Two-Canal Mandibular Incisors

    Directory of Open Access Journals (Sweden)

    Sedigheh Khedmat

    2016-01-01

    Full Text Available Objectives: This study aimed to assess the radicular wall thickness in mandibular incisors with two canals and find the maximum and minimum thickness to prevent root canal treatment (RCT procedural errors.Materials and Methods: A total of 160 extracted mandibular incisors were selected and radiographed; out of which, 55 had two canals. Three parallel transverse sections were made in each tooth at 1mm below the cementoenamel junction (CEJ, mid-root and 1 millimeter to the apex. Specimens were evaluated under a stereomicroscope and the thickness of radicular walls in each section was determined for the buccal, lingual and proximal surfaces. Data were statistically analyzed using Pearson’s correlation coefficient test.Results: The thickness of radicular wall decreased from the cervical towards the apex. In all three sections (cervical, mid-root and apical, the thickness of lingual wall was significantly greater than the buccal wall. Also, the thickness of buccal and lingual walls was significantly higher than that of the proximal walls.Conclusion: The lingual radicular wall had the highest thickness in two-canal mandibular incisors. Therefore, in these teeth, the lingual canal is a better choice for post placement.Key words:

  18. Superresolution improves MRI cortical segmentation with FACE

    DEFF Research Database (Denmark)

    Eskildsen, Simon Fristed; Manjón, José V.; Coupé, Pierrick

    Brain cortical surface extraction from MRI has applications for measurement of gray matter (GM) atrophy, functional mapping, source localization and preoperative neurosurgical planning. Accurate cortex segmentation requires high resolution morphological images and several methods for extracting...

  19. The Diversity of Cortical Inhibitory Synapses

    Directory of Open Access Journals (Sweden)

    Yoshiyuki eKubota

    2016-04-01

    Full Text Available The most typical and well known inhibitory action in the cortical microcircuit is a strong inhibition on the target neuron by axo-somatic synapses. However, it has become clear that synaptic inhibition in the cortex is much more diverse and complicated. Firstly, at least ten or more inhibitory non-pyramidal cell subtypes engage in diverse inhibitory functions to produce the elaborate activity characteristic of the different cortical states. Each distinct non-pyramidal cell subtype has its own independent inhibitory function. Secondly, the inhibitory synapses innervate different neuronal domains, such as axons, spines, dendrites and soma, and their IPSP size is not uniform. Thus cortical inhibition is highly complex, with a wide variety of anatomical and physiological modes. Moreover, the functional significance of the various inhibitory synapse innervation styles and their unique structural dynamic behaviors differ from those of excitatory synapses. In this review, we summarize our current understanding of the inhibitory mechanisms of the cortical microcircuit.

  20. A flexible dual-mode proximity sensor based on cooperative sensing for robot skin applications

    Science.gov (United States)

    Huang, Ying; Cai, Xia; Kan, Wenqing; Qiu, Shihua; Guo, Xiaohui; Liu, Caixia; Liu, Ping

    2017-08-01

    A flexible dual-mode proximity sensor has been designed and implemented, which is capable of combining capacitive-resistive detection in this paper. The capacitive type proximity sensor detecting is defined as mode-C, and the resistive type proximity sensor detecting is defined as mode-R. The characteristics of the proximity sensor are as follows: (1) the theoretical mode is developed which indicates that this proximity sensor can reflect proximity information accurately; (2) both sensing modes are vertically integrated into a sandwich-like chip with an 8 mm × 12 mm unit area. The thickness of a mode-R sensing material (graphene nanoplatelets) and mode-C dielectric (the mixture of carbon black and silicone rubber) is 1 mm and 2.5 mm, respectively; (3) for mode-R, the linearity of temperature-resistance curve can achieve 0.998 in the temperature range from 25°C to 65°C. And for mode-C, various materials can be successfully detected with fast response and high reversibility. Meanwhile, the study compensated the influence of object temperature to ensure mode-C properly works. A cooperative sensing test shows that R-C dual modes sense effectively which can enlarge the sensing distance compared with the single mode proximity sensor. The fabrication of this sensor is convenient, and the integrity of a flexible sandwich-like structure based on dual modes is beneficial to form arrays, which is suitable to be used in skin-like sensing applications.

  1. A flexible dual-mode proximity sensor based on cooperative sensing for robot skin applications.

    Science.gov (United States)

    Huang, Ying; Cai, Xia; Kan, Wenqing; Qiu, Shihua; Guo, Xiaohui; Liu, Caixia; Liu, Ping

    2017-08-01

    A flexible dual-mode proximity sensor has been designed and implemented, which is capable of combining capacitive-resistive detection in this paper. The capacitive type proximity sensor detecting is defined as mode-C, and the resistive type proximity sensor detecting is defined as mode-R. The characteristics of the proximity sensor are as follows: (1) the theoretical mode is developed which indicates that this proximity sensor can reflect proximity information accurately; (2) both sensing modes are vertically integrated into a sandwich-like chip with an 8 mm × 12 mm unit area. The thickness of a mode-R sensing material (graphene nanoplatelets) and mode-C dielectric (the mixture of carbon black and silicone rubber) is 1 mm and 2.5 mm, respectively; (3) for mode-R, the linearity of temperature-resistance curve can achieve 0.998 in the temperature range from 25  ° C to 65  ° C. And for mode-C, various materials can be successfully detected with fast response and high reversibility. Meanwhile, the study compensated the influence of object temperature to ensure mode-C properly works. A cooperative sensing test shows that R-C dual modes sense effectively which can enlarge the sensing distance compared with the single mode proximity sensor. The fabrication of this sensor is convenient, and the integrity of a flexible sandwich-like structure based on dual modes is beneficial to form arrays, which is suitable to be used in skin-like sensing applications.

  2. Morphometric differences in planum temporale in schizophrenia and bipolar disorder revealed by statistical analysis of Labeled Cortical Depth Maps

    Directory of Open Access Journals (Sweden)

    J Tilak eRatnanather

    2014-08-01

    Full Text Available Differences in cortical thickness in the lateral temporal lobe, including the planum temporale (PT, have been reported in MRI studies of schizophrenia (SCZ and bipolar disorder (BPD patients. Most of these studies have used a single-valued global or local measure for thickness. However, additional and complementary information can be obtained by generating Labelled Cortical Depth Maps (LCDMs, which are distances of labeled gray matter voxels from the nearest point on the gray/white matter (inner cortical surface. Statistical analyses of pooled and censored LCDM distances reveal subtle differences in PT between SCZ and BPD groups from data generated by Ratnanather et al. (Schizophrenia Research, http://dx.doi.org/10.1016/j.schres.2013.08.014. These results confirm that the left PT (LPT is more sensitive than the right PT in distinguishing between SCZ, BPD and healthy controls. Also confirmed is a strong gender effect, with a thicker PT seen in males than in females. The differences between groups at smaller distances in the LPT revealed by pooled and censored LCDM analysis suggest that SCZ and BPD have different effects on the cortical mantle close to the gray/white matter surface. This is consistent with reported subtle changes in the cortical mantle observed in postmortem studies.

  3. Potential gray matter unpruned in adolescents and young adults dependent on dextromethorphan-containing cough syrups: evidence from cortical and subcortical study.

    Science.gov (United States)

    Qiu, Ying-Wei; Lv, Xiao-Fei; Jiang, Gui-Hua; Su, Huan-Huan; Ma, Xiao-Fen; Tian, Jun-Zhang; Zhuo, Fu-Zhen

    2017-10-01

    Adolescence is a unique period in neurodevelopment. Dextromethorphan (DXM)-containing cough syrups are new addictive drugs used by adolescents and young adults. The effects of chronic DXM abuse on neurodevelopment in adolescents and young adults are still unknown. The aim of this study was to investigate the differences in cortical thickness and subcortical gray matter volumes between DXM-dependent adolescents and young adults and healthy controls, and to explore relationships between alternations in cortical thickness/subcortical volume and DXM duration, initial age of DXM use, as well as impulsive behavior in DXM-dependent adolescents and young adults. Thirty-eight DXM-dependent adolescents and young adults and 18 healthy controls underwent magnetic resonance imaging scanning, and cortical thickness across the continuous cortical surface was compared between the groups. Subcortical volumes were compared on a structure-by-structure basis. DXM-dependent adolescents and young adults exhibited significantly increased cortical thickness in the bilateral precuneus (PreC), left dorsal lateral prefrontal cortex (DLPFC. L), left inferior parietal lobe (IPL. L), right precentral gyrus (PreCG. R), right lateral occipital cortex (LOC. R), right inferior temporal cortex (ITC. R), right lateral orbitofrontal cortex (lOFC. R) and right transverse temporal gyrus (TTG. R) (all p adolescents dependent on DXM. These structural changes might explain the neurobiological mechanism of impulsive behavior in adolescent DXM users.

  4. Cortical Neural Computation by Discrete Results Hypothesis.

    Science.gov (United States)

    Castejon, Carlos; Nuñez, Angel

    2016-01-01

    One of the most challenging problems we face in neuroscience is to understand how the cortex performs computations. There is increasing evidence that the power of the cortical processing is produced by populations of neurons forming dynamic neuronal ensembles. Theoretical proposals and multineuronal experimental studies have revealed that ensembles of neurons can form emergent functional units. However, how these ensembles are implicated in cortical computations is still a mystery. Although cell ensembles have been associated with brain rhythms, the functional interaction remains largely unclear. It is still unknown how spatially distributed neuronal activity can be temporally integrated to contribute to cortical computations. A theoretical explanation integrating spatial and temporal aspects of cortical processing is still lacking. In this Hypothesis and Theory article, we propose a new functional theoretical framework to explain the computational roles of these ensembles in cortical processing. We suggest that complex neural computations underlying cortical processing could be temporally discrete and that sensory information would need to be quantized to be computed by the cerebral cortex. Accordingly, we propose that cortical processing is produced by the computation of discrete spatio-temporal functional units that we have called "Discrete Results" (Discrete Results Hypothesis). This hypothesis represents a novel functional mechanism by which information processing is computed in the cortex. Furthermore, we propose that precise dynamic sequences of "Discrete Results" is the mechanism used by the cortex to extract, code, memorize and transmit neural information. The novel "Discrete Results" concept has the ability to match the spatial and temporal aspects of cortical processing. We discuss the possible neural underpinnings of these functional computational units and describe the empirical evidence supporting our hypothesis. We propose that fast-spiking (FS

  5. VAGUS NERVE STIMULATION INHIBITS CORTICAL SPREADING DEPRESSION

    OpenAIRE

    Chen, Shih-Pin; Ay, Ilknur; de Morais, Andreia Lopes; Qin, Tao; Zheng,Yi; Sadhegian, Homa; Oka, Fumiaki; Simon, Bruce; Eikermann-Haerter, Katharina; Ayata, Cenk

    2016-01-01

    Vagus nerve stimulation has recently been reported to improve symptoms of migraine. Cortical spreading depression is the electrophysiological event underlying migraine aura, and a trigger for headache. We tested whether vagus nerve stimulation inhibits cortical spreading depression to explain its anti-migraine effect. Vagus nerve stimulation was delivered either non-invasively through the skin or directly by electrodes placed around the vagus nerve unilaterally. Systemic physiology was monito...

  6. Fracture load and survival of anatomically representative monolithic lithium disilicate crowns with reduced tooth preparation and ceramic thickness

    OpenAIRE

    Nawafleh, Noor A; Hatamleh, Muhanad M; Öchsner, Andreas; Mack, Florian

    2017-01-01

    PURPOSE To investigate the effect of reducing tooth preparation and ceramic thickness on fracture resistance of lithium disilicate crowns. MATERIALS AND METHODS Specimen preparation included a standard complete crown preparation of a typodont mandibular left first molar with an occlusal reduction of 2 mm, proximal/axial wall reduction of 1.5 mm, and 1.0 mm deep chamfer (Group A). Another typodont mandibular first molar was prepared with less tooth reduction: 1 mm occlusal and proximal/axial w...

  7. Connexin43 deficiency reduces the sensitivity of cortical bone to the effects of muscle paralysis.

    Science.gov (United States)

    Grimston, Susan K; Goldberg, Daniel B; Watkins, Marcus; Brodt, Michael D; Silva, Matthew J; Civitelli, Roberto

    2011-09-01

    We have shown previously that the effect of mechanical loading on bone depends in part on connexin43 (Cx43). To determine whether Cx43 is also involved in the effect of mechanical unloading, we have used botulinum toxin A (BtxA) to induce reversible muscle paralysis in mice with a conditional deletion of the Cx43 gene in osteoblasts and osteocytes (cKO). BtxA injection in hind limb muscles of wild-type (WT) mice resulted in significant muscle atrophy and rapid loss of trabecular bone. Bone loss reached a nadir of about 40% at 3 weeks after injection, followed by a slow recovery. A similar degree of trabecular bone loss was observed in cKO mice. By contrast, BtxA injection in WT mice significantly increased marrow area and endocortical osteoclast number and decreased cortical thickness and bone strength. These changes did not occur in cKO mice, whose marrow area is larger, osteoclast number higher, and cortical thickness and bone strength lower relative to WT mice in basal conditions. Changes in cortical structure occurring in WT mice had not recovered 19 weeks after BtxA injection despite correction of the early osteoclast activation and a modest increase in periosteal bone formation. Thus BtxA-induced muscle paralysis leads to rapid loss of trabecular bone and to changes in structural and biomechanical properties of cortical bone, neither of which are fully reversed after 19 weeks. Osteoblast/osteocyte Cx43 is involved in the adaptive responses to skeletal unloading selectively in the cortical bone via modulation of osteoclastogenesis on the endocortical surface. Copyright © 2011 American Society for Bone and Mineral Research.

  8. Connexin43 Deficiency Reduces the Sensitivity of Cortical Bone to the Effects of Muscle Paralysis1

    Science.gov (United States)

    Grimston, Susan K.; Goldberg, Daniel B.; Watkins, Marcus; Brodt, Michael D.; Silva, Matthew J.; Civitelli, Roberto

    2011-01-01

    We have previously shown that the effect of mechanical loading on bone is partly dependent on connexin43 (Cx43). To determine whether Cx43 is also involved in the effect of mechanical unloading, we have used botulinum toxin A (BtxA) to induce reversible muscle paralysis in mice with a conditional deletion of the Cx43 gene in osteoblasts and osteocytes (cKO). BtxA injection in hind limb muscles of wild type (WT) mice resulted in significant muscle atrophy and rapid loss of trabecular bone. Bone loss reached a nadir of about 40% at 3 weeks post-injection, followed by a slow recovery. A similar degree of trabecular bone loss was observed in cKO mice. By contrast, BtxA injection in WT mice significantly increased marrow area and endocortical osteoclast number, and decreased cortical thickness and bone strength. These changes did not occur in cKO mice, whose marrow area is larger, osteoclast number higher, and cortical thickness and bone strength lower relative to WT mice in basal conditions. Changes in cortical structure occurring in WT mice had not recovered 19 weeks after BtxA injection, despite correction of the early osteoclast activation and a modest increase in periosteal bone formation. Thus, BtxA-induced muscle paralysis leads to rapid loss of trabecular bone and to changes in structural and biomechanical properties of cortical bone, neither of which are fully reversed after 19 weeks. Osteoblast/osteocyte Cx43 is involved in the adaptive responses to skeletal unloading selectively in the cortical bone, via modulation of osteoclastogenesis on the endocortical surface. PMID:21590735

  9. Elastic Properties of Chimpanzee Craniofacial Cortical Bone.

    Science.gov (United States)

    Gharpure, Poorva; Kontogiorgos, Elias D; Opperman, Lynne A; Ross, Callum F; Strait, David S; Smith, Amanda; Pryor, Leslie C; Wang, Qian; Dechow, Paul C

    2016-12-01

    Relatively few assessments of cranial biomechanics formally take into account variation in the material properties of cranial cortical bone. Our aim was to characterize the elastic properties of chimpanzee craniofacial cortical bone and compare these to the elastic properties of dentate human craniofacial cortical bone. From seven cranial regions, 27 cylindrical samples were harvested from each of five chimpanzee crania. Assuming orthotropy, axes of maximum stiffness in the plane of the cortical plate were derived using modified equations of Hooke's law in a Mathcad program. Consistent orientations among individuals were observed in the zygomatic arch and alveolus. The density of cortical bone showed significant regional variation (P  E2  > E1 . Shear moduli were significantly different among regions (P < 0.001). The pattern by which chimpanzee cranial cortical bone varies in elastic properties resembled that seen in humans, perhaps suggesting that the elastic properties of craniofacial bone in fossil hominins can be estimated with at least some degree of confidence. Anat Rec, 299:1718-1733, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  10. Industrial Computed Tomography using Proximal Algorithm

    KAUST Repository

    Zang, Guangming

    2016-04-14

    In this thesis, we present ProxiSART, a flexible proximal framework for robust 3D cone beam tomographic reconstruction based on the Simultaneous Algebraic Reconstruction Technique (SART). We derive the proximal operator for the SART algorithm and use it for minimizing the data term in a proximal algorithm. We show the flexibility of the framework by plugging in different powerful regularizers, and show its robustness in achieving better reconstruction results in the presence of noise and using fewer projections. We compare our framework to state-of-the-art methods and existing popular software tomography reconstruction packages, on both synthetic and real datasets, and show superior reconstruction quality, especially from noisy data and a small number of projections.

  11. Correlation between social proximity and mobility similarity.

    Science.gov (United States)

    Fan, Chao; Liu, Yiding; Huang, Junming; Rong, Zhihai; Zhou, Tao

    2017-09-20

    Human behaviors exhibit ubiquitous correlations in many aspects, such as individual and collective levels, temporal and spatial dimensions, content, social and geographical layers. With rich Internet data of online behaviors becoming available, it attracts academic interests to explore human mobility similarity from the perspective of social network proximity. Existent analysis shows a strong correlation between online social proximity and offline mobility similarity, namely, mobile records be